The MPEG LA is not a patent troll. You probably have heard of their products as they are some of the most famous codecs and supported by multitudes of devices. They are using patents exactly as they were designed for.
You've obviously not kept up with recent events, they just recently sued Apple, HTC and RIM over smartphone patents that they own themselves, not part of any standard:
http://thepriorart.typepad.com/the_prior_art/2010/04/mobilem...