Reminds of a law here in Sweden and how car surveillance work on the bridge to Denmark. The law forbids the unnecessary registration of people so in order to avoid breaking the law the police have a live system in place where information of a car on the danish side get show on a screen on the Swedish side, giving border and toll guards enough time to react. The whole thing is legal only because the system operate live and never store any data, which otherwise would create a illegal register with personal information.