My completely baseless speculation is that there was something in the mansion that Vinny wanted.
First, when everyone was running around panicking over the Cathy Cluck, that sneaky fuck Nick was searching for something in the library (sure, the laptop was found in the library, but if that was the case, why was Nick still looking there?)
When Nick couldn't find whatever it was, Vinny came in (with his gang maybe?) and tossed the joint looking for whatever it was (drugs or money I'm guessing) and just frames the jocks for the break in.
Remember, the library was Vinny's old room, so something being left there (given how fucked up the room used to be), does make some sense.
The only fly in the ointment are the dildos. How did Vinny get hold of all of them since the last time we saw them, they were being thrown through the Alpha's windows?
Dildos are still an ultra incriminating element for Jokes.Sooo... let me get this straight... you " deduce " that Vinny has this whole masterplan... fucks up the DIK mansion frames the DIKless gang BUT is in fact incapable to sneak in just as easily into the idiots " mansion " and grab the rubber cocks ( for his leisure ) ?
The DIKs have just returned them, and an hour or two later they are found in the DIKs house.
I don't see how Vinny, in such a short time, can get the same ones, and then go with several guys on campus to trash the house.
It's necessarily the Jocks, but that doesn't rule out Vinny being involved. He may have a mole at the Jocks, or leverage on them (Chad's secret, drugs).