Jeez. GameStop is not the only place where people can trade-in games! There is Amazon.com and CraigsList.org. At Amazon.com, people looking to unload their old titles can make back a respectable amount of money, as long as they copy they have is well taken care of. CraigsList is completely free. Yeah, you have to deal with spider-bots sending you scripted emails, but that comes with the territory.
Come on, people! Think! If/When you want to sell off your old games, and make some money back, don't go to GameStop! They will rip you off every single time! Go through Amazon or Craigslist.
Oh yeah. Selling stuff online means you won't have to give up your thumbprint! Not all people trading in games are crooks, for chrissakes.