The German constitutional court began to hear the case of data law that 34,000 people sued against on Tuesday. The data law allows authorities to require communications companies to store telephone and Internet data for six months if it can help with police investigations. It was introduced in 2008 by the former 'grand coalition' government, which brought Germany into line with a European Union directive of 2006. Germany constitutional court, based in Karlsruhe in the state of Baden- Wuerttemberg, was to examine 60 separate legal questions regarding the law, which was the biggest class action in the court 's history. Justice Minister Sabine Leutheusser-Schnarrenberge and former Interior Minister Gerhart Baum, both from Liberal Free Democrats ( FDP), are among the complainants who sued against the law. Baum said the law is 'without doubt in breach of the constitution,' and it affects all citizens' lives and privacy. It could be used to gather huge amounts of information, which could tell whom a person was talking to and where a person was. However, this law was strongly supported by German police. Konrad Freiberg, head of Germany's police union, said: 'Take the Sauerland group, for example, which planned attacks in Germany, or the terrible attacks in Madrid -- in these cases, tracking down further offenders was only possible thanks to the data storage measures.' Freiberg also said he understood why people worried about this law as 'we have witnessed a lot of data abuse by private companies. ' 'But I must stress that the police has not let data be abused and there is judicial control at all times,' he added. This is a tough hearing faced by Germany's highest court and a decision is expected to come out till next spring. 