Nothing you did, it is just how the Network admins have set for a filter on Proxy traffic. If a website request carries certain keywords, then the proxy can either accept or deny the request. One wrong word added to the list, or to a websites metatags, and no one in our Domain will be able to get to it.
Yes. This has happened to internal, work related, websites as well.
Well, if it doesn't work when you get home, let me know. If it doesn't work most of the time I'll try to figure something else out.