CCTVs (Close Circuit Televisions) were developed in UK primarily as a guard against the IRA bombings.
Night vision security cameras with in-built infrared illuminators allow you to see even in complete darkness.
UK has 20% of all the CCTVs in the world.
Footage from security cameras have been used as evidence to solve many murder cases, most notably the Soho nail bomber and the murder of two-year old Jamie Bulger.