tedster - 11:29 pm on Aug 21, 2012 (gmt 0)

Sounds like you are actually describing a "soft 404" here - that is, a variety of URLs that all return a 200 OK http status but all show the same content even when the URLs are different.

I think a 403 Forbidden would be more appropriate. A 200 OK indicates that the actual content was returned, and in this case it isn't - the content you're sending is a kind of error message.