LinkedIn Corp., owner of the world's biggestprofessional-networking website, confirmed reports that some userpasswords were compromised in a security breach.

The Mountain View, California-based company apologized tocustomers in a blog post and said that members will know if theiraccounts were affected because their passwords will no longer bevalid.

“We take the security of our members very seriously,” thecompany said. The service has more than 160 million users.

LinkedIn said on its Twitter Inc. micro-blogging site earliertoday that it was investigating reports of stolen passwords. Thecompany cites security issues as a risk for investors in regulatoryfilings, and disclosed as recently as last month that it hasexperienced website disruptions and outages for reasons including“denial of service or fraud or security attacks.”

Future disruptions were possible, according to the May 7 filing.Breaches demonstrate a need for U.S. legislation to help safeguarddata, a member of Congress said.

“How many times is this going to happen before Congress finallywakes up and takes action?” U.S. Representative Mary Bono Mack, aCalifornia Republican who heads a House Energy and Commercesubcommittee that has looked at online-privacy issues, said in astatement. “This latest incident once again brings into sharp focusthe need to pass data protection legislation.”

LinkedIn sent its first Twitter message, or tweet, this morningtelling users that it was looking into the issue and followed up atabout 11:20 a.m. New York time, saying nothing was confirmed. Aspokeswoman, Erin O'Harra, said LinkedIn would continue to updateusers on Twitter.

Password Tips

LinkedIn advised users never to change passwords by following ane-mail link, as “those links might be compromised and redirect youto the wrong place.” The company's website has a “Settings” pagewhere changes can be made.

“In order for passwords to be effective, you should update youronline account passwords every few months or at least once aquarter,” the company said on Twitter, while listing tips onpassword creation.

While the company didn't mention any specific attacks in itsregulatory filings, Reuters reported in May 2011 that the websitehad “security flaws” that made accounts vulnerable to hackers,citing a security researcher who identified the problem.

LinkedIn rose less than 1 percent to $93.08 at the close in NewYork, after earlier falling as much as 1.5 percent. The stock hasmore than doubled since the company's initial public offering inMay 2011.

Bloomberg News

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