There are reasons that are possibly not announced...
At my school in Cleveland Ohio we were at one point not allowed to access cleveland.com's forums because there was a serious threat made that was investigated by the FBI to one of the students.
Yet the same bad press came up about my school from the story and they exactly left out the reasoning and made it a blame catholocism smear..
The FBI arrested several people etc. Yet none of this made the news, but the fact of them simply keeping us off cleveland.com was what was publicized.
