Universities, like most other schools in general, maintain huge block-lists and heuristic filters for things like piracy, porn, malware, and anything else they deem to be unacceptable uses of their networks.

On top of the network censorship, most schools and libraries also engage in or are pressured to engage in censoring books and other print material for the same reasons. http://www.pfaw.org/report/schools-and-censorship-banned-boo...

Kind of ironic that the official forefront of education is also the foremost consumer of censorship tools but I think the concerned parents are still winning on this one.