NEW YORK (

TheStreet

) -- Facebook users' personal information has been made available to third parties, in particular advertisers, through online applications over the past few years,

Symantec

(SYMC) - Get Report

said in its

official blog

.

These third parties accidentally had access to personal account information, such as profiles, photographs and chat, and could have had the ability to post messages, the security software maker said.

Facebook applications may be leaking users' personal information to third parties.

"We estimate that over the years, hundreds of thousands of applications may have inadvertently leaked millions of access tokens to third parties," the security software company said in a blog post on Tuesday.

Up to 20 million Facebook applications are installed every day, according to the social networking site, which are then integrated onto the Facebook platform.

"We estimate that as of April 2011, close to 100,000 applications were enabling this leakage," Symantec said. "Fortunately, these third parties may not have realized their ability to access this information."

Symantec said it notified Facebook of the leakage. Now the world's largest social networking Web site says it is taking "corrective action to help eliminate this issue."

"Unfortunately,

Symantec's resulting report has a few inaccuracies," Facebook spokeswoman Malorie Lucich said in a statement. "Specifically, we have conducted a thorough investigation which revealed no evidence of this issue resulting in a user's private information being shared with unauthorized third parties."

Lucich said the report also ignores the contractual obligations of advertisers and developers which prohibit them from obtaining or sharing user information in a way that "violates our policies."

However, she confirmed that Facebook removed the outdated API (Application Programing Interface) referred to in Symantec's post.

--Written by Theresa McCabe in Boston.

>To contact the writer of this article, click here:

Theresa McCabe

.

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