If you're interested in outrageous and/or senseless perversions of justice, go to http://reason.com and follow their Daily Brickbat. (You'll have to deal with the magazine authors being a bunch of Libertarians; naturally, you may or may not appreciate this.) A good number of incidents involve schools, of course.

Sample: 'Marshall Junior High School in Texas bars students from having "designs shaved into their hair." So when Sheldon Williams showed up for classes with lines shaved into his hair officials took a permanent marker and filled in those lines.' -- http://reason.com/brickbat/2011/10/18/thats-leave-a-mark

You may also want to follow Radley Balko who's focus is criminal justice & the legal system. He was at Reason for several years, he is now at Huffington Post.