Authenticity badges were popping up at Twitter on Friday as the popular micro-blogging service tested a way to verify that people tweeting are who they claim to be.
Twitter accounts for celebrities Ashton Kutcher and Oprah Winfrey bore blue seals containing white check marks to indicate the identities were verified.
Kutcher's verified account had more than two million followers. There were dozens of others tweeting in his name.
There was also a verified Twitter account for four-time NBA champion Shaquille O'Neal of the Phoenix Suns.
Impersonation has been a bane for Twitter, which earlier this year suspended a bogus account set up in the name of the Tibetan spiritual leader, the Dalai Lama.
St Louis Cardinals baseball team manager Tony La Russa filed a lawsuit last month against San Francisco-based Twitter over a bogus account set up in his name.
Twitter founder Biz Stone explained in an online message that the verification experiment will begin with "public officials, public agencies, famous artists, athletes, and other well known individuals at risk of impersonation."
"We hope to verify more accounts in the future but due to the resources required, verification will begin only with a small set," he added.
Launched in August 2006, the micro-blogging service has been embraced by U.S. President Barack Obama, singer Britney Spears, bicyclist Lance Armstrong and other politicians, artists and athletes.© Wire reports