I was stunned to read that British police use new anti-terror powers to stop and search people every three minutes. Section 44 of the Terrorism Act has been used 170,000 to search people in 2008 alone according to the BBC. (See: BBC NEWS | England | London | Capital sees rise in terror stops.) These searches have led to 65 arrests (0.035% success) and zero convictions (0.000% success). Of course there are no official stats on how many times Section 44 was used as a pretense for some other motive.
Draw your own conclusions.