I just went to check on some recent posts of another member, and clicked on the "search other posts by xxxxx" icon next to their user name on the thread, and also get the stern "function not permitted" message.

Why are NOT all these things covered by an announcement? It is getting that many of the regular features have been disabled with no advice given to regular users.

I doubt this function gets much use and puts much drain on the system, but it very useful when you need to use it.