Seems like all we every hear about is what you should do in Disney. What rides are good, what dining locations are good, where to find characters, and so on. I want to mix things up. I thought I'd warn people about things they should avoid at all costs. I will warn you that these items are the result of actual events. I really wish that was a joke...
Don't feel up Minnie Mouse or any other character: Yes you will get removed from the parks but that's not all. The last guy who felt up Minnie Mouse got arrested and convicted.
No touchy, touchy in the wave pools: This should really be common sense. However, it's happened. If it's your spouse or other close person save it for the bedroom. If you don't know the person don't do it. A man was arrested and convicted because he "accidently" touched some people in the wave pool.
Don't punch the characters: Another one that should be common sense. Sadly it has happened. In fact one character punched back. I don't blame him. I think I'd take my head off and beat the guy with it.
Don't dump ANYTHING in the water on the water rides: In the worst example I've heard of (not sure if it's an urban legend) someone dumped a relatives ashes into the water in pirates. In Florida ashes are considered a bio hazard. They had to close the ride, drain the water, and sanatize the track.
Don't do it they can see you: If you are in Disney World you are on camera. Keep that in mind before you pick your nose, butt, scratch your privates, spit, go at it with a girlfriend on a dark ride, or any other shenanigans.
Don't drink too much alcohol: Booze and rides are not a good combo but an even worse combo is alcohol and the hot Florida weather. People will laugh at you if you pass out and need to be taken to first aide.
Don't flash on the ride photos: Yes Disney did away with the people who review the ride photos but that doesn't mean it's ok to flash. You'll just upset all the parents who are trying to have fun with their kids. Although there are two groups who will thank you - perverts and teenage boys.
That is the short list. I think you get the point. If there are any others you'd like to see, go ahead and post them in the comments.