This is an excerpt from the show on ID Scams that was on Oprah - this is the one thing that caught my eye the most, thought i'd mention it here!
Shield Your Fortune with a $2 Pen
All it takes to empty your bank account is a single signed check stolen from your unlocked mailbox and some acetone-the active ingredient in nail polish remover. (Conveniently for criminals, pure acetone is also available in the paint department of home improvement centers.) Here's how the scam goes down: The crook steals mail likely to contain a signed check-envelopes addressed to the phone or electric company are easy pickings. He or she then removes your check, puts a piece of cellophane tape over the front and back of your signature, and places the check in a pan of acetone. This process-known as "check washing"-takes only about 30 minutes to rinse everything but the printer's ink from the check. Your tape-covered John Hancock and the printer-inked information, of course, remain intact. The check is then blow-dried and flattened in a book, the tape is carefully peeled away and voilà-a blank check signed by you, replete with your name, address and bank account information.
How to Protect Yourself
Buy yourself a safe pen. One type of ink-the kind in gel pens manufactured by Uni-Ball-resists acetone or other chemicals used in check washing.