Bicycle theft

Bicycle theft is the crime of stealing a bicycle.
Rates.
According to the International Crime Victim Survey (2000), 56% of bicycle thefts across 17 countries were reported to the police. According to an estimate from the NCVS there was an estimated 1.3 million incidents of theft of or theft from bicycles. 
According to the British Transport Police, theft and bicycle damage has grown 67% between 1999 and 2005.
A 2007 report by the Birmingham Community Safety Partnership in Birmingham, England, found that the majority of bike thieves were males under the age of 20. According to a bicycle theft study in Ellensburg, Washington, approximately 80% of stolen bicycles are stolen for enjoyment or transportation services.
The London Cycle Theft Survey (2016), by Stolen Ride and London Cycling Campaign, 55% reported being 'very concerned' with the security of their bikes out and about in London.
The FBI publishes the percentage of bikes reported stolen each year in their yearly edition of "Crime in the United States" which is available on the FBI’s website, www.fbi.gov. In 2019, bicycles represented 3.1% of larceny-theft reported, second only to motor vehicles. 
Types of offenders.
Although many bicycle thefts occur by offenders looking for financial gain, other offenders can be categorized into the following categories regarding their motivation.
Perpetrator techniques.
There are a variety of methods of stealing bikes.
Lock jamming.
"KGW" news in Portland reports according to local experts they've interviewed, thieves jam things into victim's lock to prevent their key from working and go strip the bike of components while it is left unattended while the owner tries to figure out how to get it unjammed.
Prevention.
Bicycle theft is a common crime committed in areas with high population as well as on college campuses. According to the Police Department at the University of Colorado, Boulder, it was found that most bicycle thefts involved bikes being unlocked, improperly locked, or locked with devices such as a lightweight cable or low-quality U-lock devices.
One can prevent bicycle theft by avoiding using bicycles with quick release wheels, as these are easy for anyone to take off without the use of any tools. Furthermore, one should use a strong U-lock to secure their bike. One should only lock his or her bike to sturdy structures and should not leave the bike in one place for too long. 
The way in which the bike is locked to the structure is also important. It is important that both a wheel and the frame of the bike are locked to a structure so that a thief cannot steal a wheel and leave the bike, or vice versa. A former London bike thief recommended small and stiff d-locks, as they are hardest to cut.
An study published in 2012 in "PLOS One" examined the watching-eye effect as it applied to bicycle theft. The researchers simply placed clearly visible signage saying "Cycle Thieves: We Are Watching You" (along with the words "Operation Crackdown" and the logo of local police) at locations on a university campus in England that had frequently seen bicycle theft. The study found that in the year following the signage's installation, bike thefts decreased by 62% in the locations with the signs, "but increased by 65% in the control locations, suggesting that the signs were effective, but displaced offending to locations with no signs."