5.  The first applicant, Mr Kovyazin, was born in 1986 and lives in Kostino, Kirov Region. The second applicant, Mr Savelov, was born in 1979 and lives in Moscow. The third applicant, Mr Gushchin, was born in 1988 and lives in Khimki, Moscow Region. 6.  On 6 May 2012 a public demonstration entitled the “March of Millions” was held in central Moscow to protest against the allegedly rigged presidential elections. The event had been approved by the city authorities in the form of a march followed by a meeting at Bolotnaya Square which had to end at 7.30 p.m. Numerous clashes between the police and protesters occurred when the marchers arrived at Bolotnaya Square. At 5.30 p.m. the police declared the early closure of the meeting and began to disperse the participants. It took them about two hours to clear the protestors away from the square. 7.  On the same day the Moscow city department of the Investigative Committee of the Russian Federation opened criminal proceedings to investigate the suspected mass disorders and violent acts against the police (Articles 212 § 2 and 318 § 1 of the Criminal Code). On 18 May 2012 the file was remitted to the headquarters of the Investigative Committee for further investigation. On 28 May 2012 the investigation was also launched into the criminal offence of organising mass disorders (Article 212 § 1 of the Criminal Code). The two criminal cases were joined on the same day. 8.  All applicants took part in the demonstration of 6 May 2012 at Bolotnaya Square. They were arrested on later dates indicated below and charged with participation in mass disorders; the second and the third applicants were also charged with having committed violent acts against the police officers. They were detained and tried on these charges, and the second and the third applicants have been convicted as charged, while Mr Kovyazin had been exempted of liability under the Amnesty Act. 9.  The complaints to be examined in the present case concern various aspects of the applicants’ pre-trial detention. 10.  From 2006 to 2012 the applicant studied culture and history at the Vyatskiy State University in Kirov while working part-time as a video‑operator for a newspaper “Vyatskiy Nablyudatel”. On 1 May 2012 he dropped out of the university. 11.  On 4 May 2012 the applicant received an assignment from the newspaper to attend the “March of Millions” on 6 May 2012 and to take video footage of the event. 12.  The applicant claimed that on 6 May 2012 he arrived at Bolotnaya Square, filmed the event and did not take part in any disorders or clashes with the police. 13.  On 15 May 2012 the applicant submitted the footage to the newspaper and it was published on its website. 14.  Until 5 September 2012 the applicant continued working and living at his usual address. On the latter date he was detained and charged under Article 212 § 2 of the Criminal Code (participation in mass disorders). He was accused of having breached public order during the demonstration on 6 May 2012, in particular, of having turned over portable toilet cabins and having piled them on the road to build a barrier obstructing the riot police. 15.  On 7 September 2012 the Basmannyy District Court of Moscow ordered the applicant’s pre-trial detention until 5 November 2012 on the grounds of the gravity of the charges and for the following reasons:
“Having regard to the circumstances of the offence under investigation, the personality of the accused, the information objectively put forward by the investigating authority, the court concludes that [the applicant], if at liberty, after being charged with a grave criminal offence will prefer, out of fear of sanctions, to abscond the investigation and trial, [or] may act in person or through proxy with the aim of avoiding criminal liability, continue [his] criminal activity, destruct the evidence and otherwise obstruct the investigation.
Operational-search activities are now underway, aimed at establishing [the applicant’s] possible connections with other active participants of the mass disorders which took place at Bolotnaya Square in Moscow and the adjacent territory, therefore, if at liberty, [he] may co-ordinate his position with unidentified accomplices whose identities are still being established by the investigation.
...
... selecting in respect of [the applicant] another, milder, preventive measure is not possible because it cannot rule out the very possibility for the suspect to obstruct the investigation of the criminal case, and to abscond from the bodies of criminal prosecution and trial.
...
No factual information excluding the detention of [the applicant] on health grounds has been submitted to the court ...” 16.  On 1 October 2012 the Moscow City Court upheld the detention order of 7 September 2012. 17.  On 30 October 2012 the Basmannyy District Court of Moscow examined a request for an extension of the applicant’s pre-trial detention. The applicant requested to select another preventive measure pending trial. He offered a bail of 750,000 Russian roubles (RUB), or four personal guarantee signed by his professors and colleagues. His request for an alternative preventive measure was supported by six petitions signed by 45 journalists and editors of newspapers, periodicals and on-line media: “Novaya Gazeta”, “Esquire”, “Kommersant”, “Vyatskiy Nablyudatel”, “Afisha” and “Grani.ru”. The applicant also requested release on health grounds. 18.  On the same day the court granted an extension of the applicant’s pre-trial detention until 6 March 2013, having noted that the applicant was likely to abscond, to continue his criminal activity, to threaten witnesses, or to otherwise obstruct the course of justice. 19.  On 28 November 2012 the Moscow City Court upheld the extension order of 30 October 2013. 20.  On 4 March 2013 the Basmannyy District Court granted an extension of the applicant’s pre-trial detention until 6 July 2013, essentially on the same grounds as before. 21.  On 3 April 2013 the Moscow City Court upheld the extension order of 4 March 2013. 22.  On 24 May 2013 the applicant’s criminal case was transferred to the Zamoskvoretskiy District Court of Moscow for the determination of the criminal charges. 23.  On 6 June 2013 the latter court granted another extension of the applicant’s detention until 24 November 2013. This decision concerned eleven defendants and read in so far as relevant as follows:
“... the court concludes that the preventive measure in respect of [all defendants] ... is to remain unchanged because the reasons taken into account when these measures were chosen have not ceased to exist and have not changed ...
... [the defendants] are accused of [grave crimes punishable by prison sentences] ...
Having regard to all information about the personality of [the defendants] and the nature of the crimes imputed to each of them, the court still has sufficient grounds to believe that the said defendants, if at liberty, may flee the trial or otherwise obstruct the course of justice, [motivated by] the gravity of the charges.
... no other measures of restraint would secure the aims and goals of the judicial proceedings.” 24.  On 2 July 2013 the Moscow City Court upheld the extension order of 6 June 2013. 25.  On 19 November 2013 the Zamoskvoretskiy District Court granted another extension of detention in respect of nine defendants, including the applicant. It ordered their detention until 24 February 2014 on the grounds of the gravity of charges. It held, in particular, as follows:
“[The defendants] are charged with a criminal offence provided for by Article 212 § 2 of the Criminal Code, which belongs to the category of grave crimes punishable by a prison sentence of over three years. Furthermore, [some defendants] are charged with a criminal offence provided for by Article 318 § 1 of the Criminal Code, also punishable by a prison sentence of over three years.
Despite the defendants being registered as having permanent residence addresses in the Russian Federation, the analysis of the overall information about [the defendants’] personalities, and the nature of the offences imputable to them, give the court sufficient grounds to consider that the defendants, if the preventive measure is changed to another one unconnected with the deprivation of liberty, may flee the trial or otherwise obstruct the course of justice, [motivated by] the gravity of the charges ... the reasons taken into account when these measures were chosen have not ceased to exist and have not changed ...” 26.  On 17 December 2013 the Moscow City Court upheld the extension order of 19 November 2013. 27.  On 18 December 2013 the State Duma passed the Amnesty Act which concerned persons charged with offences punishable with prison sentences of up to five years. 28.  On 19 December 2013 the applicant requested the termination of the criminal proceedings against him by operation of the Amnesty Act. On the same day the Zamoskvoretskiy District Court granted the request and released him from detention. 29.  At the time of arrest he applicant was unemployed and lived with his parents. On 6 May 2012 he took part in the demonstration at Bolotnaya Square. According to the applicant, at one point a stampede occurred and he was accidentally pushed through the police cordon and was arrested without any resistance on his part. On the same day he was charged with non‑compliance with a lawful order by a police officer, an offence under Article 19.3 of the Code of Administrative Offences, and he was released, having committed to attend the court hearing of the administrative case on 8 May 2012. 30.  On 8 May 2012 the applicant was convicted of non-compliance with a lawful order by a police officer, an offence under Article 19.3 of the Code of Administrative Offences. He was sentenced to a 24-hour’ detention. 31.  On 11 June 2012 the applicant was detained on suspicion of having participated in mass disorders on 6 May 2012. He was charged with the offences provided for by Articles 212 § 2 of the Criminal Code (participation in mass disorders) and 318 § 1 (violence against a public official). He was accused, in particular, of having attempted to break through the police cordon and of having pulled a police officer on the hands and wrists towards the crowd. On the same day the Basmannyy District Court authorised the applicant’s 72-hours’ detention. 32.  On 14 June 2012 the Basmannyy District Court examined and granted the request to detain the applicant pending criminal investigation. It dismissed the applicant’s request for an alternative preventive measure, including a RUB 150,000 bail, a personal guarantee or a house arrest, and ordered the applicant’s detention on remand until 11 August 2012 for the following reasons:
“Assessing the circumstance under investigation, the submitted materials and the indicated information in their integrity, as well as the personality of [the applicant], who is suspected of having committed criminal offences characterised as grave, punishable by up to two years of deprivation of liberty, give sufficient reasons to believe that the applicant is likely to abscond, to continue his criminal activity, to destruct evidence, or to otherwise obstruct the investigation of the criminal case.
... selecting another, milder, preventive measure is not possible because it cannot rule out the very possibility that the suspect will abscond from the bodies of criminal prosecution and trial, or obstruct the investigation of the criminal case.” 33.  On 18 June 2012 the applicant filed an appeal, which was dismissed by the Moscow City Court on 11 July 2012. 34.  On 9 August 2012 the Basmannyy District Court examined a request for an extension of the applicant’s pre-trial detention. The applicant objected, having reiterated his request for an alternative preventive measure. On the same day the court extended the applicant’s pre-trial detention until 6 November 2012, having noted that there remained sufficient reasons to believe that the applicant was likely to abscond, to continue his criminal activity, to threaten witnesses, or to otherwise obstruct the course of justice. 35.  On 10 August 2012 the applicant filed an appeal, which was dismissed by the Moscow City Court on 10 September 2012. 36.  On 2 November 2012 the Basmannyy District Court granted another extension of the applicant’s detention, until 6 March 2013, essentially on the same grounds and having noted that the circumstances which had justified the detention order had not changed. This extension order was upheld by the Moscow City Court on 28 November 2012. 37.  On 28 February 2013 the Basmannyy District Court granted another extension of the applicant’s detention, until 11 June 2013, essentially on the same grounds as before and having noted that the circumstances which had justified the detention order had not changed. This extension order was upheld by the Moscow City Court on 17 April 2013. 38.  On 23 April 2013 the Moscow City Court examined a fresh request for the extension of the applicant’s detention and granted it until 6 July 2013. It held, in particular, as follows:
“The materials presented [by the investigator] reveal that the grounds for choosing the preventive measure in respect of [the applicant] were not only the gravity of the charges but also the information about the personality of [the applicant] who could abscond the investigation and trial, threaten witnesses or otherwise obstruct the proceedings in the case, if released.
The aforementioned grounds ... have not changed, have not lost their relevance to date, and the circumstances of the case [and] the nature of the crime committed by [the applicant] lead the court to conclude that the need for the [pre-trial detention] has not, at this stage, ceased to exist.
...
This term is reasonable, [it] is justified by the objective circumstances, it is not in conflict with the term of the pre-trial investigation, also extended on the same grounds.
...
In accordance with the Constitutional Court’s [case-law], the proportionality of the preventive measure to the [gravity of the] charges imputed to [the applicant] show that in this case the public interests, in particular those related to the criminal investigation, override the importance of the principle of respect of individual liberty.” 39.  On 27 June 2013 the Moscow City Court acting as appeal instance upheld the same court’s extension order of 23 April 2013. 40.  On 24 May 2013 the applicant’s criminal case was transferred to the Zamoskvoretskiy District Court for the determination of the criminal charges. 41.  On 6 June 2013 the latter court extended the pre-trial detention of all eleven defendants, including the applicant, until 24 November 2013 (see paragraph 23 above). This decision was upheld by the Moscow City Court on 2 July 2013. 42.  On 19 November 2013 the Zamoskvoretskiy District Court granted another extension of detention in respect of nine defendants, including the applicant, until 24 February 2014 (see paragraph 25 above). This extension order was upheld by the Moscow City Court on 17 December 2013. 43.  On 21 February 2014 the Zamoskvoretskiy District Court found the applicant guilty as charged. He was sentenced to two years and seven months of imprisonment. The applicant’s pre-trial detention was counted towards the prison term. 44.  On 20 June 2014 the Moscow City Court upheld the first-instance judgment. 45.  In December 2014 the applicant was released after having served his prison term. 46.  At the time of his arrest the applicant was a student, working part‑time. On 6 May 2012 he took part in the demonstration at Bolotnaya Square, and after that date until 6 February 2013 he continued living at his usual address and pursued his usual activities. 47.  On 6 February 2013 the applicant’s flat was searched and his travel passport was seized. The applicant was arrested on suspicion of having participated in mass disorders and of having used violence against the police during the demonstration of 6 May 2012. He was charged with the offences provided for by Articles 212 § 2 of the Criminal Code (participation in mass disorders) and 318 § 1 (violence against a public official). He was accused, in particular, of having snatched a police officer’s uniform and pulling him away to prevent him from arresting another protestor. 48.  On 7 February 2013 the Basmannyy District Court ordered the applicant’s pre-trial detention until 6 April 2013, having dismissed the applicant’s request for an alternative preventive measure, such as house arrest. The court reasoned as follows:
“In assessing the circumstances of the offence under investigation, the personality of the accused , who is suspected of having committed criminal offences one of which is characterised as grave and the other – of medium gravity, the court concludes that [the applicant], if at liberty, after being charged with a grave criminal offence, will prefer, out of fear of sanctions, to abscond the investigation and trial, [or] may act in person or through proxy with the aim of avoiding criminal liability, continue [his] criminal activity, destruct the evidence and otherwise obstruct the investigation.
Operational-search activities are now underway, aimed at establishing [the applicant’s] possible connections with other active participants of the mass disorders which took place at Bolotnaya Square in Moscow and the adjacent territory, therefore, if at liberty, [he] may co-ordinate his position with unidentified accomplices whose identities are still being established by the investigation.
The aforementioned circumstances are corroborated by the operational-search materials submitted to the investigator and the court under the procedure provided for by law.
Taking into account that ... [the applicant] has been [previously] charged with an administrative offence ... and that [he] has a travel passport and thus has no obstacles to travelling abroad ... the house arrest may not be granted.” 49.  On 27 February 2013 the Moscow City Court upheld the detention order of 7 February 2013. 50.  On 1 April 2013 the Basmannyy District Court extended the applicant’s pre-trial detention until 6 August 2013, on the grounds that the circumstances that had justified the detention – the gravity of charges and the risk of obstructing the course of justice – had not changed. 51.  On 24 April 2013 the Moscow City Court upheld the detention order of 1 April 2013. 52.  On 1 August 2013 the Basmannyy District Court granted an extension of the applicant’s pre-trial detention on the following grounds:
“The investigator’s request indicates that ... during the investigation [the applicant] was making contradictory statements thus obstructing the investigation of the criminal case. Moreover, during the investigation it was found out that [the applicant] has acquaintances outside Moscow and the Moscow Region. Therefore, if [he] is subjected to a preventive measure other than detention in custody he may flee the investigation and trial.
... the victim and eye-witnesses have indicated [the applicant] as the perpetrator ...
...
[He] is charged with criminal offences one of which is of medium gravity and another is a grave one, punishable by over three years of deprivation of liberty.
...
These circumstances are substantiated, real, corroborated by the information about the defendant’s personality, including [the information] obtained through operational-search activities.” 53.  On 28 August 2013 the Moscow City Court upheld the detention order of 1 August 2013. 54.  On 1 October 2013 the Basmannyy District Court granted a new extension of the applicant’s detention, until 6 February 2014. In its reasoning it stressed the complexity of the case, reiterated the grounds given in the previous orders and noted that the circumstances which had justified the detention order had not changed. The Moscow City Court upheld the extension order on 23 October 2013. 55.  On 20 November 2013 the indictment was issued to the applicant, with the final charges defined under Articles 212 § 2 and 318 § 1 of the Criminal Code. 56.  On 3 February 2014 the Moscow City Court examined a fresh request for the extension of the applicant’s detention and granted it, until 6 June 2014. The court justified this extension as follows:
“The extension of the [applicant’s] pre-trial detention is necessary because of the need to allow him and his counsel sufficient time for access to the investigation case file, which has not been finished.
... the [applicant’s] partners in crime have not all been identified and have not been arrested, he knows the personal details of the victims and the witnesses accusing him of being the perpetrator. Taking into account the total of the aforementioned circumstances, the court considers that [the applicant] is likely to flee the investigation and trial, to continue his criminal activity, to put pressure on the victims and witnesses, to induce them to give false evidence, to destruct evidence or to otherwise obstruct the course of justice in the criminal case.” 57.  On 27 February 2014 the Moscow City Court acting as appeal instance upheld the same court’s detention order of 3 February 2014. 58.  On 14 April 2014 the Zamoskvoretskiy District Court granted another extension of detention in respect of three defendants, including the applicant. It ordered their detention until 30 September 2014 on the following grounds:
“The reasons taken into account by the court for selecting the preventive measure... have not changed [and] have not lost their relevance to date.
...
The Court takes into account the nature, the gravity and the factual circumstances of the offence imputable to the defendants, the existence of the unidentified perpetrators of the mass disorders, as a real ground for the defendants’ possible unlawful conduct.
Considering the foregoing, it is obvious that the defendants [M.,], [the applicant] and [G.], if at liberty, may abscond or otherwise obstruct the course of criminal procedure” 59.  On 18 August 2014 the Zamoskvoretskiy District Court found the applicant guilty as charged. He was sentenced to two years and six months of imprisonment. The applicant’s pre-trial detention counted towards the prison sentence. 60.  The applicant is currently serving the remainder of the prison term. 61.  From 8 September 2012 to 9 June 2013 the first applicant was detained in remand prison IZ-77/4, consecutively in five different cells. In each cell the applicant had at least four square metres of personal space and an individual bed at all times; he had one hour of daily outdoor exercise. 62.  According to the Government, the applicant underwent a medical examination on his admission to IZ-77/4; on his request he received medical assistance on 8 November 2012, 9 January 2013 and 20 May 2013 and on 4 December 2012 he had a specialist consultation with an ophthalmologist. 63.  On 9 June 2013 the applicant was transferred to IZ-77/2. According to the Government, the cell allowed the applicant at least four square metres of personal space and he had an individual bed at all times; the toilet was separated by a solid partition from the rest of the cell in order to ensure the necessary privacy; the cells were treated for disinfection and pest-control once every three month and whenever necessary; the applicant was entitled to one-hour outdoor exercise per day; the cell was cleaned and the beddings were changed once a week; the cells were equipped with forced ventilation and could be aired through the hinged window pane. The artificial light was provided at 100 watt by day and at 75 watt by night. The glazed windows let in daylight. 64.  On 7 October 2013 and 20 October 2013 the public commission for the monitoring of detention facilities visited IZ-77/2. The applicant made no complaints about the conditions of his detention.