In general, you don't need a posted sign to use a video camera in a public area, like in front of your house, or a private area that is not open to the public, like your back yard. But talk to an attorney before installing cameras where there is a reasonable expectation of privacy.
You want to put up a security camera in your home or business and you're wondering: Do I have to post a sign for video surveillance? The answer depends in part on where you live and in part on the area the cameras will film.
TL;DR (Too Long; Didn't Read)
State laws differ but, in general, you do not need to post a sign to use a video camera in a public area, like in front of your house, or a private area that belongs to you and is not used by the public, like your back yard. But you may need to be careful if you are thinking of putting surveillance cameras in public bath rooms, changing rooms, or anywhere someone has a reasonable expectation of privacy.
Benefits of Surveillance
Most people agree that surveillance cameras make the country safer. They make criminals less bold in city streets and private businesses open to the public, and also make it much more likely that the criminals will be caught. A picture truly is worth a thousand words, especially when those words are the testimony of store employees trying to recall what the bank robber looked like when they were terrified during the robbery. And in court, video evidence is very hard to dispute or deny.
Federal Law Does Not Regulate Surveillance
It seems surprising, but the fact is, the federal government does not regulate surveillance cameras. Federal laws have very little to say on how to balance the interests of privacy with the right to video your home or business. The Fourth Amendment to the Constitution provides protection to individuals against unreasonable or unwarranted searches and seizures, and it comes closest to providing some kind of federal protection.
Public Areas vs. Areas with an Expectation of Privacy
The vast majority of regulation in this area is at the state level, and, as usual, state laws differ. In general, the laws do not forbid surveillance of public areas, like streets, parks, public parking lots and beaches, nor do they require that notice be posted of the presence of surveillance cameras. Likewise, a homeowner using video within her own home is generally unregulated.
Some states, including New York and California, forbid the use of video cameras in areas where individuals have a reasonable expectation of privacy. These locations include bathrooms, changing rooms, bedrooms and and any other place people might undress. In some states, if there are cameras in these areas, a notice must be posted letting the public know.
In about a quarter of the states, laws also prohibit electronic surveillance in places where most people expect privacy. Most of these states also forbid trespassing on private property to conduct surveillance of people there. There are also state laws preventing audio recordings of people who have not given their consent.
In practice, most businesses who employ video surveillance cameras also post a video surveillance notice sign. But, as of right now, you are not legally required to post these signs for public area surveillance.