Zynga, itself being sued by Mob Wars creator Psycho Monkey for IP issues regarding the Zynga title Mafia Wars, has now filed suit against other leading rival Playdom for misuse of the mark “Mafia Wars” in ads it is running for its popular game, Mobsters.

Sound confusing? That’s because these kinds of IP issues are still by and large very common in the social gaming world. Late last year, SGN settled its suit with former employee David Maestri over ownership of Mob Wars, but suits have continued to fly since.

In this case, Zynga’s complaint alleges Playdom used the Mafia Wars mark in its ads for Mobsters illegally:

In the past month, Playdom has run an advertisement that misleadingly associates its Mobsters game with the more popular Mafia Wars game and with Zynga. Zynga brings this action to enjoin Playdom from continuing to post the advertisement online or in any other forum, to obtain damages, and to require Playdom to engage in corrective advertising to remedy the confusion caused by its advertisements.

We’ll let you know how Playdom responds. The company just brought in former EA COO John Pleasants last week.

A copy of the suit, via ContentNext, is below: