2 attorney answers
Hidden cameras SHOULD NOT be in private areas such as a bathroom when you are inviting guests into the home. So if a person wants to say "its my home" and puts a camera in his bathroom, then he can never let anyone in that bathroom or he needs to disable the camera...otherwise he is committing a crime.
Otherwise, he can have cameras in the central and gathering areas of the home. The recordings can only be used in court IF at least one party to the recording agrees. So if you and the owner appear in a recording it is ok. If the owner leaves you alone and records you, that is not ok. BUT remember that you have no expectation of privacy in someone else's home...particularly in the "common areas" such as a living room and those recordings could be used in a criminal court if a crime were committed.
Camera's should not be placed in areas where someone would have an expectation of privacy . . . like the restroom. If you are recorded using the restroom, there would be a a basis to charge the homeowner with a crime. Best of luck!
The information provided by Attorney Matthew V. Silva is based upon the generic and ambiguous facts presented in short questions. Without a full consultation with an attorney, you should not rely upon any information presented in this forum. The intricate facts of every case are different. The information provided is not legal advice and should not be the basis of any decision without the actual guidance of an attorney. Further, any information provided by Attorney Matthew V. Silva should not be perceived as a willingness to represent you or actual representation.