Well I guess we’ll work out two things very quickly: 1. Is it worthwhile giving free labour to these services by generating their content, and, 2. Do we want

Well I guess we’ll work out two things very quickly: 1. Is it worthwhile giving free labour to these services by generating their content, and, 2. Do we want to login and/or pay to check user generated content? Personally, I think the answer will be no. If these services generated their own content, which we actually value, then it would be a different matter. But they don’t, so if they put up road blocks I suspect they will get a bit of a shock to learn they aren’t actually as vital to society as they thought they were.