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 Maryland, video surveillance laws align with the general principle that it is legal to record or surveil individuals without their consent in areas where there is no reasonable expectation of privacy. This means that in public spaces or visible areas within a private setting, such as a retail store or a workplace, the use of surveillance cameras is typically permissible. However, Maryland law prohibits video surveillance in areas where individuals have a reasonable expectation of privacy, such as dressing rooms, bathrooms, and similar private spaces. The use of 'nanny cams' or other hidden cameras in one's home is generally legal, provided they are not placed in areas where privacy is expected. It is important to note that while video surveillance is allowed in many circumstances, audio recording often has stricter regulations, and Maryland is a two-party consent state for audio recordings, meaning that all parties involved in a conversation must consent to being recorded. Violations of these laws can result in both civil and criminal penalties. To ensure compliance with Maryland's specific statutes and case law regarding privacy and surveillance, it is advisable to consult with an attorney.