We have a network manager who controls access to the web. Kids have restricted access for obvious reasons. Staff have access to other sites such as YouTube, which does contain some fantastic stuff for teaching and learning. My advice is to get in touch with your union officials who can take this matter up with your authority's LNCT (local negotiating committee for teachers). It's daft not to allow teachers access to sites which could enhance learning. If they use it inappropriately, then there should be consequences, but that's what being a professional is all about.