Engadget is reporting via a number of tipsters that the popular PlayStation emulator PSX4Droid has been pulled from Android market. Google's statement on the issue?

"We remove apps from Android Market that violate our policies."

Well, that's helpful. Actually, upon a short perusal of the US Patent and Trademark Office database, the reason became clear to us: PSX4Droid is infringing on a trademark owned by Sony for the acronym "PSX." This means PSX4Droid probably just needs a name change before being given the green light for republication. Considering the impending release of the Xperia Play, Sony seems to have timed its complaint rather strategically.

Another PlayStation emulator, FPSe, was not removed - lending considerably credence to the trademark infringement theory.

On a somewhat related note, speculation that N64oid has been pulled from the Market for similar reasons is apparently false. The developer of the app decided to remove it from the market himself in order to take some time to get it performing at an acceptable level, according to a few sources. However, it's worth noting that Nintendo of America does hold the "N64" trademark, so really, it's anyone's guess until we hear from the developer.