AT&T this week was hit with a federal class action in California, accusing the telephone giant of requiring its information technology staff to remain on call at all times of the day for trouble-shooting, but not paying them for the work performed while on call.

On the opposite end of the country, a similar class action was filed last month in New York against T-Mobile USA, accusing that company of requiring sales associates and supervisors to be on call “all hours of the day,” but not paying them for such off-the-clock tasks as responding to e-mail and text messages.