Don't give them any ideas. They have enough bad ones as it is... hahavBulletin 4 resembles IPB 3. I guess IPS used a time machine and traveled into the future to see what iNet was doing with vB and they should also sue IPS, yesirreee!
/Huge Amount of Sarcasm
In essence it can be argued that vB 4 looks like many other software or web apps that came before it. If this is truly the case, why is XF being targetted only? We won't know the real reason until the case is made public.