I don't know if you ever watched the West Wing, but there was a recurring character named "Harry Klaypool" who represented a group called "Freedom Watch", and who basically just filed endless lawsuits and subpoenas to try to harass and dig up dirt on the show's fictional presidential administration (to which he was politically opposed).
That character was based on... Larry Klayman and "Judicial Watch", which basically do the same thing in real life (i.e., file nuisance suits against the administration whenever a Democrat is in office).
This is a guy who, from what I can tell, would file a massive lawsuit on the news that a Democratic President slept in for five minutes one morning. It's about the least credible basis for challenging PRISM that you'll find.