Personally, I say no. Used games have already been sold once new, and so it's not like the game developers and publishers are actually losing anything. The other day, I was at GameStop, and some random jerk saw I was buying a used game that was $50 new. He went up to me and said "Hey, y'know, you're ruining the industry by buying used games." Being the civilized person I am, I suppressed the urge to say "Back off, jerk", and instead replied that the game had already been sold for $50, and I was simply buying it for a reduced price that goes to someone else.
It's not like Ford or Lincoln sees someone buy a used car and says "Dang it, there goes our profits right down the crapper!" They already made a profit, and it's downright greedy for them to feel cheated if they can't make twice as much off a single product. I, for one, don't have $50 to burn on a game I might hate, and so I pay less for a game that's already been sold.
It's a similar deal with downloadable games. I don't want to pay $60 to download some PC game I might be able to get for $50, especially because I have dial-up and it'll take four days to get the thing on my hard drive. Same goes for downloadable mini-games on consoles: I have a PS2 and GameCube, and I have no intention right now of getting a 360 or PS3 (or even Wii), since they all, in some way or another, require getting broadband, which my family simply can't afford right now.
So, in closing, I'd like to see everyone's opinion on this topic. That's why this is a pole, of course.