Several companies now are setting rules about what employees can post even if they are off the clock.
An attorney for the California Chamber of Commerce says businesses are entitled to limit postings if employees are chatting about things like company secrets, or harassing a coworker online.
"Usually what employees do after hours is their own business," Susan Kemp said. "However, what is the impact on the workplace? You know are all these people tied together on Facebook and friends and so everybody in the organization knows about it and now there's this huge rumor mill."
Kemp says companies can even stop workers from using their own Blackberries or other personal devices at work if it slices into work time.