On Twitter, stock talk is ‘buyer beware’

Investors can't just buy Apple stock because of billionaire investor Carl Icahn's comments on Twitter, StockTwits CEO Howard Lindzon said Wednesday.

"It's a little bit of theater," he said. "But guess what, Carl's taking risk when he does this because if he's wrong three times in a row with a tweet, people will ridicule him. So, he's playing the game. Some people don't like it. Seems quite legal to me. There's a lot of people upset, but get used to this."

Icahn made headlines on Tuesday after he used Twitter to announce that he had taken a "large position" in Apple, followed by criticisms after shares of the Cupertino, Calif., company topped $500.

(Read more: Carl Icahn's effect on Apple: Traders weigh in)

Lindzon, who founded and heads StockTwits, a website that allows users to have real-time conversations about the market, said on CNBC's "Fast Money,"that he saw nothing wrong with what Icahn had done.

"People want to broadcast, share ideas, converse," he said. "Icahn's no different."

Lindzon said that his site differed from the pump-and-dump stock chat rooms of an earlier era, adding that it was instead "trying to take away the spam."

Lindzon also said that his site was about "taking down the walls."

"Everybody is allowed to talk about stocks," he added. "That's the way I feel about it. The walls have come down. The technology is there. We're all holding this mood ring right at the tip of our fingers, and we want to say stuff. We want to share pictures. Contextually, it's buyer beware. We've got to be careful of the context that we take everything.

"You can't just buy Apple because Carl Icahn said so. And so that doesn't change. People need to grow up. It's your money, you've got to be responsible with it."

By CNBC's Bruno J. Navarro. Follow him on Twitter @Bruno_J_Navarro.

— CNBC's Michael Newberg contributed research to this report. Follow him on Twitter: @MikeNewberg.

Trader disclosure: On Aug. 14, 2013, the following stocks and commodities mentioned or intended to be mentioned on CNBC's "Fast Money" were owned by the "Fast Money" traders: Steve Grasso is funds long FCX; Steve Grasso is funds long MU; Steve Grasso is long BA; Steve Grasso is long BAC; Steve Grasso is long BBRY; Steve Grasso is long GDX; Steve Grasso is long GOOG; Steve Grasso is long HERO; Steve Grasso is long HPQ; Steve Grasso is long MHY; Steve Grasso is long LNG; Steve Grasso is long MJNA; Steve Grasso is long NVIV; Steve Grasso is long PFE; Steve Grasso is long QCOM; Steve Grasso is long S; Steve Grasso is long ASTM; Steve Grasso is long POT; Steve Grasso is long DECK; Karen Finerman is long AAPL; Karen Finerman is long BAC; Karen Finerman is long C; Karen Finerman is long TGT; Karen Finerman is long GOOG; Karen Finerman is long M; Karen Finerman is long SPY; Karen Finerman is long MDY PUTS; Dan Nathan is long FB; Dan Nathan is long JCP; Dan Nathan is long WFM; Dan Nathan is long XCO; Dan Nathan is long VIX; Dan Nathan is short IWM; Brian Kelly is long US dollar; Brian Kelly is short Yen T-Notes.