Does anyone else realize that Americans are owned by their employers?

My husbands regular hours are roughly 7-4 Monday through Friday but he rarely works that. In addition to these hours he has a cell phone where he is expected to be on call 24/7. Last Saturday he ended up working 8am to 12 midnight. Then yesterday they sent him home at 1:30pm. Today he got a good day in but then right after super he got called to a service call. We cannot make plans. We have no life at all. He was told that if he can't be on call on a weekend to tell them so h did for the 9th of Septemeber but has already been asked to work anyway despite telling them weeks in advance that he would be off! When does it end? Are all employers this way? My hubby said that pretty much all employers expect their emplyees to be there for them 24/7. Is this true?