The details of the story are hard to find nowadays, probably because the lawyers told everyone to shut up about it. You can find some vague allusions to it here: " Wolfram quit Illinois, took the program private, and entered into complicated lawsuits with both his former employee and his co-authors (all since settled)." http://vserver1.cscs.lsa.umich.edu/~crshalizi/reviews/wolfra...

Btw, which side of his reputation does he live up to? To being a visionary genius or to being a raving crank?