Look here at the "real" image?
https://bitcointalk.org/index.php?topic=432741.msg4804408 (not saying he is a scammer or that's not the real image) People on the forums and all over eBay and the net write their name on a piece of paper to show they are real.
within 5 mins a friend did this... imagine if he took longer.
The point is writing on a piece of paper your username doesn't mean shit. Always trade with protection. escrow, ebay or however. But don't be rude, be willing to protect the seller to.