Here we go. If a lot of harmless or potentially even useful material gets blocked, people who want to use that material will simply opt out or route round the blocking, hence making it pointless.
I kind of hope they overreach drastically for exactly that reason. It'll be a lot easier to get the filters dropped entirely if we can attack them with "useful website X is blocked for no good reason" over and over and over again, than if we have to argue using examples that many people would actually have a problem with.
OK, so I'll be keeping an eye on personal Web sites put up by teachers (of which there are many, a couple of examples[1], [2], neither blocked to my knowledge) that can be accessed from UKERNA provided College connections but become blocked by domestic connections.