Lawyers are calling it social networking burnout. Back-to-back studies, the most recent issued Tuesday, show a big chunk of corporate America is banning communication wonders like Twitter and Facebook from the workplace.

According to the latest survey of more than 1,400 U.S. companies, more than half (54 percent) said they prohibit employees from visiting sites such as Twitter, Facebook and MySpace while on the clock. The survey, by Robert Half Technology, a provider of information technology staffing services, was based on telephone interviews with U.S. companies of 100 or more employees.