I can actually top the magic marker story.
Someone tried robbing a bank, right?
His disguise was lemon juice.
He knew it could be used as an invisible ink, so his logic went something like this:
"if it can make word bye-bye it can make ME bye-bye"
and so he promptly rubs lemon juice on his face, goes into the bank, and tried to rob the place.
Doesn't work, needless to say.