Something I've noticed over the past few weeks is how many big commercial websites use jQuery combined with lots of plugins - but don't admit it. They will rename the main library to something obscure, as well as the plugins. Quite a few will even remove the comments that contain the MIT/GPL license information. (just noticed today that odeon.co.uk have done exactly this)
Why are they doing this? are they abashed by the face that they are using a free and open source library?