July 8 (Bloomberg) -- Sarah Palin’s clash with people impersonating her on Twitter has spotlighted the challenge celebrities face in managing what’s Tweeted about them.

Palin, after resigning as governor of Alaska last week, warned on July 4 that fake Tweets about her were untrue.

“Unfortunately fake ‘Gov Sarah Palin’ twitter sites r doing their thing today,” Palin, the former vice-presidential candidate, said in a post on Twitter. “So sorry if u recv false info @ fake site.”

Twitter Inc., which lets users post 140-character messages online, said last month that it is testing a feature that would add the word “verified” to some accounts to distinguish real and fake users. While Palin’s account is verified, more than a dozen accounts, including “hockymom64” and “EXGovSarahPalin,” use Palin’s name or title, and some show her photo.

The question of how to handle fake profiles will become increasingly important to Twitter as more people rely on the service, said Ray Valdes, an analyst with research firm Gartner Inc. in San Jose, California. The site had an estimated 17.6 million users in the U.S. in May, a more than 27-fold increase from a year earlier, according to researcher ComScore Inc. in Reston, Virginia.

“Twitter does need to strengthen its notion of identity as it plays a greater role in the public conversation if it wants to have impact,” Valdes said in an interview.

Following Brands

Palin’s office and the press department of San Francisco- based Twitter didn’t respond to requests for comment.

Closely held Twitter could make money by verifying accounts used by companies promoting products, co-founder Biz Stone said in an interview last month. Users following brands would know it was really Dell Inc. or Coca-Cola Co. sending Tweets, Stone said.

Palin joins a list of celebrities, including singer Britney Spears and actor Jeff Goldblum, who have been impersonated on Twitter or have had false information spread about them. In the past month, both Spears and Goldblum had to correct fake Tweets that announced their deaths.

Twitter is the third-largest U.S. social-networking site, behind Facebook Inc. and News Corp.’s MySpace, according to ComScore.

To contact the reporters on this story: Brian Womack in San Francisco at bwomack1@bloomberg.net; Ian King in San Francisco at ianking@bloomberg.net

Last Updated: July 8, 2009 00:01 EDT