@Foxfyre,
they used to block basic sites like yahoo, hotmail, and espn.
other sites were accessible within a "quota" timeframe (including A2k!).
last year they switched to sophos, and granted us access to everything.
sophos is (to quote the head of our IT dept) "considered the leading anti-virus software in the Business industry",
and was touted as being the ultimate barrier for all the malicious crap.
i think it's possible FB use is being abused here -- many co-workers have accounts...
interestingly, twitter is NOT being blocked... although that may change as well...