A perfect example of why I hold this opinion is the currently blog-swarming case of Corey Maye:
Let's summarize: Cops mistakenly break down the door of a sleeping man, late at night, as part of drug raid. Turns out, the man wasn't named in the warrant, and wasn't a suspect. The man, frigthened for himself and his 18-month old daughter, fires at an intruder who jumps into his bedroom after the door's been kicked in. Turns out that the man, who is black, has killed the white son of the town's police chief. He's later convicted and sentenced to death by a white jury. The man has no criminal record, and police rather tellingly changed their story about drugs (rather, traces of drugs) in his possession at the time of the raid.
(More details at BattlePanda.)
Lets put it this way: even the conservative blogs are screaming over this one (it's the tiny Libertarian gene in their make-up. It occasionally makes them vulnerable). Pass it around, folks and when any addresses for appeals letters pop up, I'll post them.
* In retrospect, that single sentence contains my entire political philosophy.