Apart from the warnings that you will be spied upon, possibly spammed, and have toolbars foisted upon you, apparently you're not allowed to transcode FROM DivX to anything else:

"NO TRANSCODING: You are prohibited from using this software with a software or hardware product whose purpose is to "transcode" or convert DivX video or DivX Media Format content into an alternate format."

Not only is this clause laughable and unenforceable, it's inexcusable. Imagine rendering out an animation from your favorite 3D package to a DivX movie (I know, it's not the smart way to work but just bear with me for this theoretical scenario). You then realize it should have been H.264, and to make that deadline you need to transcode it rather than rendering it out all over again.

But wait! Taken at face value, you're PROHIBITED from changing the format of your OWN data that YOU created! Can you imagine being prohibited from exporting your 100-page Word document to RTF? Or "transcoding" that TIFF to a JPEG?

My response can only be "Um... How about a big hot cup of GoToHeck?!"