Jan. 7 (Bloomberg) — LinkedIn Corp., operator of the biggest professional networking site, said hackers using automated software created thousands of fake member accounts and copied data from actual member profile pages.

The practice, known as data "scraping," violates LinkedIn's user agreements and federal and state computer fraud laws, the company said in a complaint filed yesterday against the unknown hackers in federal court in San Francisco. It has also strained and disrupted the company's network computers and threatens to degrade the value of LinkedIn Recruiter, a fee- based service used by Fortune 100 companies that's one of the company's fastest-growing offerings, according to the complaint.

"It undermines the integrity and effectiveness of LinkedIn's professional network by polluting it with thousands of fake member profiles," Jonathan Blavin, a lawyer for the company, said in the complaint.