Ann Kiernan replies:
It is OK to videotape employees at work, so long as they are not someplace where they have a legitimate expectation of privacy, such as the bathroom or locker room. While federal law and the laws of most states also allow audiotaping, there are about a dozen states, including California, where you cannot audiotape without everyone’s permission. So, while you can legally film the sleeping, you may not be able to record the snoring!
Information here is correct at the time it is posted. Case decisions cited here may be reversed. Please do not rely on this information without consulting an attorney first.