Is it illegal to record someone's voice without their knowledge?

Answer 1

This depends on the state governing the law regarding "Taped conversation." In many states, both parties need to be made aware of the recording and further; it needs to be displayed on the recording of advisement and consent to record. There are a few states that require just one party to be advised of a recording device, and it has to be prominently displayed on the recording as well. In all states, barring a few, there must be a warrant to record conversations where all parties are unaware they are being recorded.

Answer 2

Not in most cases. I believe there are some situations where you can but I am not sure. ~*~*~ If you have an open case against you, and a detective, cop, ect; is recording you then yes. They do need a warrent in most cases if not all though. If it is in any other case then I don't think they are aloud to record you without your permission or something in your families permission. (Ex.: 'What Not To Wear' secretly films you for an ex amount of time, but they have your family\friends permission.)

Answer 3

It is illegal in most countries, unless at least one of the people being recorded is aware that they are being taped.

Answer 4

No, there are certain privacy laws that state you cannot film someone without their permission, especially if you put it on the internet.