Legality of surveillance equipment depends on the state you are in, the type of equipment being used, as well as how the actual equipment is being used. For example, the state of Florida is a one party consent state so you have to let the other party know they are being recorded before you are allowed to record audio. However, for video you can record as long as you aren't invading somebody's privacy. It is important you check with state laws prior to using any equipment.