I saw this on a regualr basis: Basically, something would cause the disc to become unbalanced in the drive while spinning. Sometimes it was the label on the disc, sometimes it was a problem with the drive itself. Either way, when the disc became unbalanced, it would sometimes make contact with the actual tray and leave very pretty concentric rings on the disc. After that, once you get to that point in the disc, a movie would stutter like a coke addict and most games would simply lock-up.
I know there was an epedemic of this with Madden 2003 when it first came out. I’d say more than 25% of the people that bought it at my store came back within a week. All of them had the rings on the discs.