Internet Brands...
LOL...Internet Brands bought vBulletin because they thought it would be a nice cash cow for them. Immediately upon buying the company, they radically scaled back the investment and development on the next version of the product, the features of which had already been publically announced to their user base. Instead, IB decides to greatly water down the enhancements, and then promise the rest "over the course of several longer-term releases". In short, whenever they might decided to finance the work.
So the best of their development team leaves...because they could see the writing on the wall. Apparently IB thought that their old dev team would be happy working at Wall Mart, or really do anything other than, say write bulletin board software (which is all they know, having done it for so long).
Now IB is faced with the introduction of a far superior competitor, written to be what the promised version of vBullitein was SUPPOSED to be...and on a newer framework.
So of course...you can now see the genesis of this lawsuit.. IB has realized that their "cash cow", their golden goose...may not be so golden after all. Reading the web forums, there are HUGE numbers of old vBulletin customers that cannot wait to switch to the new product.
What IB wants to say is "you kids were supposed to go quietly!!!". Instead, they are leading the insurrection...and are likely to make IB's investment return look exceedingly poor...