Yeah I see fucked up shit all the time, like cops lighting up just to make illegal U-turns at redlights and such. Generally you can look forward to cops doing +10mph over the speed limit, tailgating you if you do the speed limit, and ticketing you as soon as you break the speed limit.
NEVER ADMIT TO A COP THAT YOU WERE SPEEDING, AND ALWAYS ASK TO SEE THE RADAR LOCK AND THE RECORDED CODE!!! these will prove invaluable in court... and if he doesnt have them, ask him to let you off with a warning.