"Event photography is long hours and tough as it is. Add in people making it less lucrative and worth the while....."

Julie, you have hit the nail on the head with this comment. Yet in my case (and my experience) I am just as concerned about the people who are shooting/filming similar material on behalf of other exhibitors and then distributing the images/footage for free afterwards. Money or no money involved, it is undermining the OP in my opinion.

As for banning equipment - pro or otherwise, I think that would just be opening a can of worms as some people could be there for legit reasons and not trying to shaft the OP (in my case if not OP, I might be on media or other assignments). But it can be hard to establish who is doing what unless you talk to the management and there isnt always time to do this on the day. Sometimes one only finds out when its too late and the peak ordering period has been and gone...