Here's a post on the magazine blog - one of the people who lives with the Professor gives the details of the raid on their house.
Three of us stayed to watch the hazmat team come in to investigate a child’s chemistry set, to see them search the garage on an additional warrant, to sign vouchers for all the things they confiscated as “evidence”—Curious George plush toys, artwork, correspondence with political prisoner Daniel McGowan, birth certificates, passports, the entire video archive of a local media collective, tax records, books, computers, storage devices, cell phones, Buffy the Vampire Slayer DVDs, flags, banners, posters, photographs and more than can be recounted here.
The police had a warrant, but a motion has been filed asking for the items seized to be returned, since a lot of them were irrelevant and/or not even his. (Among them were copies of Steampunk Magazine. Cuz science fiction writing is totally evidence of interfering with police activity.) The Pittsburgh Post-Gazette has more details of the case.
The whole debate about what use of Twitter constitutes criminal activity is interesting, since it's so used in organizing protests - everything that happened in Iran, for example. But the search seems to have been a bit ridiculous, so hopefully the case won't get very far.