I have one guy - I know EVERYTHING about him. I keep telling his contacts to let him know he keeps giving out the wrong address. We're talking very sensitive contractual stuff. I figure it's on him by now.
The best is when the lawyers get all official with me. Yeah, no - this is your mistake, don't get all uppity that you sent sensitive stuff to the wrong address.
From time to time I think about responding with a Goatse, but that's too much even for me.