Video surveillance is generally legal in the United States and a person is not required to get the consent of the person being watched or recorded—unless the surveillance or recording is done in a place or context in which the person being watched or recorded has a reasonable expectation of privacy.

For example, in a retail store or workplace setting, the store or employer may place cameras surveilling and recording persons in the store or workplace but may not do so in dressing rooms, bathrooms, or breastfeeding or lactation rooms—which are places where persons generally have a reasonable expectation of privacy.

Similarly, people generally have a right to surveil (watch) and record persons visiting their homes—and when hidden cameras are placed inside the home they are sometimes referred to as nanny cams. For example, people sometimes want to watch and record a babysitter, nanny, cleaning service provider, repairman, pool cleaner, or other invited or uninvited guest.

It is generally legal to surveil and record such persons with or without their permission—but only in places where the persons being watched or recorded do not have a reasonable expectation of privacy. For example, it is often a civil and criminal violation of state statutes to place a hidden camera in a bathroom, shower, or changing area in which persons have a reasonable expectation of privacy.

Video surveillance laws vary from state to state and are usually located in a state’s statutes—but some relevant privacy laws and rights may also be located in a state’s court opinions—also known as its common law or case law.

In Maine, video surveillance is subject to both state statutes and expectations of privacy. While it is generally legal to conduct video surveillance in public areas or one's own property, Maine law prohibits recording in places where individuals have a reasonable expectation of privacy, such as bathrooms, dressing rooms, and similar private spaces. This means that while businesses and employers can use surveillance cameras in common areas, they must refrain from placing them in areas designated for private activities. Similarly, homeowners can use 'nanny cams' to monitor service providers or guests, but must not place cameras in private areas of the home. Violating these privacy expectations can lead to civil and criminal penalties. It's important to note that while the general principles of video surveillance are consistent, specific applications can vary, and individuals should consult an attorney for guidance on particular situations.