I can see the first one or two doing it and getting that deer-in-the-headlight look when they get caught, but after that everyone should know. What you put on the internet stays on the internet.
Rep. Weiner, apparently thought he could get away with it, but it only took a split second to hit that send button and realize “Oh Nuts! Bring it back!”.
Don’t send stuff in email, twitter, Facebook, MySpace, any social media internet based conduit that you don’t want your mother, wife, general public to see. It will always come back to haunt you.