Edited sentence: He believes that filming must be a "proportionate and reasonable" response to a crime and that this does not appear to be the case as people are being targeted over what they might do in the future.It is uncertain as to how long data collected by the unit is to be kept but GMP currently anticipate it will be stored for 5 years.Kieran Walsh, a civil liberties lawyer, said the scheme could be in controvention of Article 8 of the European Convention on Human Rights - the right to privacy.Not all of these people are suspects in crime however, people can be filmed if they are thought to associate with prolific offenders or if they have been stopped in an area of high crime under suspicious circumstances.Since the scheme launched in 2006 more than 900 hundred people have been filmed by the unit.This has resulted in several offenders being sent back to prison after breaching licence conditions