I have a theory that the DIKs mansion was originally the nerds, if you remember from the flashback to the founding of the DIKs, what is now the main party room, was another library. In that library there was a small sitting area with a table and chairs, too small for studying but likely a great place to play DnG. The nerds being the only frat without a house, and needing money enough to sell notes and such feels like a hint. Especially when tommy points out that a frat without a house is a joke. It would explain the camera being a long term installation in the closet(not why, just an explanation of how it could have been installed). It would also explain the scene in the flashback where tommy and rusty talk about someone being at the door again, i beleive it sounded like they kept getting harassed, could have been the nerds giving them shit for getting the house out from under them.
I know that this is all supposition and has no real hard evidence, but it feels like a decent guess as a start to why Magnar hates the DIKS so much, in addition to the nerds always getting picked on by them and the other greeks.
