NEW YORK (AP) -- Twitter is proving to be one costly website for J.R. Smith.
The NBA fined the New York Knicks guard $25,000 on Friday for his exchange with Detroit Pistons guard Brandon Jennings on the social media website.
The league said the penalty was for ''directing hostile and inappropriate language to another player via his Twitter account.''
Smith's latest Twitter flap - he also was fined $25,000 by the NBA last year for a racy tweet - started Wednesday after Jennings made a critical comment about Smith's little brother, Chris, who also plays for the Knicks.
Jennings noted that Chris Smith is in the NBA though Pooh Jeter and Bobby Brown aren't. J.R. Smith, saying he is tired of people disrespecting his little brother, responded with a couple of tweets, including one that appeared threatening toward Detroit and was later taken down.
''I'm always in trouble with Twitter,'' Smith said before the Knicks' 109-106 loss to Houston on Thursday night. ''I don't know what it is. Trying to shake it.''
Smith denied any bad intent, saying he and Jennings have played together in the summer and had a good relationship. He added that he didn't think his tweets were a big deal, but said coach Mike Woodson talked to him about it.
Smith said he had stayed off Twitter recently but grew tired of the criticisms of Chris, whose roster spot has been a source of controversy. Chris Smith hasn't proven himself to be an NBA player, and Woodson said during the preseason that being J.R. Smith's brother would be a factor when he decided on his final cuts.