OU has the option to discourage people from posting information about surveys, as well as deleting "confidential information" shared. If they don't do these things, OU may not be on the best side of Uni's legal department.
Yes, some other sites get away with it. There are a plethora of reasons, not all of them fair, associated with each case. But that's the situation and I can't blame the OU staff for protecting themselves.