Jeff:
http://www.guardian.co.uk/uk/menezes for just one example. Killed by London police, ensuing investigation wound up with blatantly nonsensical explanations and testimonies... everything was fucked up, and all this guy did was wear a coat. There's your first start - just the one name that came to mind, and my short-term memory (which carries information about as well as houses of cards in tornadoes) wasn't too poor to catch the name. (Again, if you can't find things like this, look harder.) Slovak officials
planted contraband on civilians to test Dublin ports. These two incidents - one just weeks ago, the other in 2005 - alone would be enough to put a sun-sized hole in your assertion, and these incidents are two of many that are within easy reach.
On filming... in a public place, with 'no expectation of privacy' as the mindbogglingly vague expression goes, filming is fine.
Jeff