Don't have the details yet, but ESPN News is apparently reporting he violated the substance abuse policy. I have no idea what that means (steroids? weed?), but I'm guessing we'll find out soon enough. Sorry I don't have a link for you -- there's nothing in Google News just yet.
Update: Here's an article from ESPN:
The NBA announced Wednesday that Pistons' point guard Lindsey Hunter has been suspended without pay for 10 games for testing positive for phentermine, a weight loss pill banned by the league.
Hunter scored 20 points, matching his total as a Pistons rookie in Golden State's 1993 win at the Palace, in Detroit's 111-93 loss to the Warriors Monday night.
Hunter's suspension will begin with Wednesday night's game between the Detroit Pistons and the Cleveland Cavaliers.
Hunter needs help losing weight? My gut reaction is that he obviously didn't take it on purpose. I guess Flip Murray will be playing against his former 'mates from Cleveland tonight. And could somebody get Will Blalock on the phone?
(Also, thanks to Larry Brown for the original tip.)
Second Update: I have some more on this up at the FanHouse, including what phentermine actually is and why athletes take it. For what it's worth, Hunter claims it was an accident:
"I took a diet pill, and it had a banned substance in it," Hunter said. "I was just as shocked as everybody else."
Hunter later said that the pill was from a prescription for his wife.
"It was my wife's prescription, and I took it," Hunter said. "I guess in our house, we've done things like that before. If I had a head cold or something, I'd grab her, whatever. It was a bone-headed mistake by me."