Whether there's an "economic downturn" or not you'll always find people who simply don't "get" the concept of paying for stuff.
I mentioned this issue on Twitter earlier today and a couple of people sent me links to these absolutely hilarious videos. Apologies if the display is a bit odd - width may be a problem:
Of course if someone owes you money they really need to pay you .. Stewie's take on this is .. well .. em .. violent?
And the followup ...