LinkedIn is an online networking site for work connections. Users can post their résumés, writing samples, film clips or other job-related materials. LinkedIn has its own "Kevin Bacon game" by showing you potential connections based on degrees of separation and mutual colleagues.

Now, four people are suing LinkedIn, saying the job site cost them employment opportunities, according to The New York Times.

The service blamed is "Reference Search." An employer can pay for the premium account status and use the search to create a list of people who worked at the same company at the same time as the applicant. The prospective employer can even message the people on the list via LinkedIn.

Sweet v. LinkedIn, a class-action suit filed in October in Northern California, contends that employers can "anonymously dig into the employment history of any LinkedIn member, and make hiring and firing decisions based upon the information they gather." Since this is done without ensuring the information obtained in accurate, the plaintiffs consider this a violation of the Fair Credit Reporting Act, according to The New York Times.

"You may never know you did not get the job based on one of these so-called references," said James L. Davidson, one of the lawyers for the plaintiffs, according to The New York Times.

"A reference search, which is only available to premium account holders, simply lets a searcher locate people in their network who have worked at the same company during the same time period as a member they would like to learn more about," spokesperson for LinkedIn Joseph Roualdes said in an email to The New York Times. "A reference search does not reveal any of that member's nonpublic information."