A new lawsuit might give employees pause in how they use social networking in the workplace.

TEKsystems is accusing three former employees of its Edina, Minnesota, office, including a woman named Brelyn Hammernik, of violating non-compete and non-solicit agreements.

In a suit filed in Minneapolis’ U.S. District Court in mid-March, Hammernik’s former employer said she wrongfully contacted former clients and co-workers—and more unusually, that her LinkedIn page could prove it.

The suit also names Hammernik’s new employer, Minnetonka, Minnesota-based Horizontal Integration Inc., as a defendant.

While working as a technical recruiter for Hanover, Maryland-based TEKsystems, Hammernik signed contracts prohibiting her from contacting clients and colleagues if she left, which she did in November. TEKsystems provides information-technology staffing and services.

In January, Hammernik joined Minnetonka’s Horizontal Integration, where she is now the company’s business development manager. Among other allegations, TEKsystems said that Hammernik, in her new job, used social-networking sites to communicate with at least 20 of TEKsystems contract employees. It cites LinkedIn connections with at least 16 TEKsystems employees as evidence.

The complaint alleges Hammernik messaged an invitation to a TEKsystems employee to visit her new workplace. TEKsystems didn’t say how it obtained the message or viewed her connections, but LinkedIn users can see the contacts that they share with Hammernik.

Winthrop & Weinstine attorney Megan Ruwe is an employment litigator who is not involved in the case but takes a special interest in social networking. Ruwe said this is the first time she’s seen someone’s LinkedIn activity cited in a lawsuit, but she expects it to happen with increasing frequency.

Some of her clients have been concerned that social-networking sites like LinkedIn can help departing employees pilfer trade secrets or client lists. “Employers are going to have to get a little bit more savvy about this and remind their employees of their continuing obligations, and that may include the use of LinkedIn,” Ruwe said.

Social-networking sites MySpace and Facebook have complied with subpoenas for data in criminal cases, she said.

LinkedIn data could make for strong evidence in employee contract cases. However, LinkedIn would likely fight such a request, she said.

LinkedIn representatives could not be reached for comment.

“Having the LinkedIn account, having those people on it may not in itself be a violation, but it’s what you do with it,” Ruwe said, adding, “If you can’t call someone and say it, and you can’t send a letter and say it, then you shouldn’t be doing it on LinkedIn.”

University of Minnesota Law School professor Thomas Cotter agreed. “There’s nothing inherently different about doing it this way and doing it the old way, other than this way is much more efficient.”

As case law develops, courts could decide whether the online connections employees make at work belong to the employee or employer. Courts, Cotter said, have “a lot of discretion” in deciding whether comparable customer lists and contacts are trade secrets and whether social-networking activity can be covered by competitive agreements.

Hammernik and a Horizontal Integration representative declined to comment on the suit to the Minneapolis/St. Paul Business Journal, as did George Wood, the Littler Mendelson attorney representing TEKsystems.