The US radio scanner laws lets you own and use the devices in your home. But some states impose restrictions on their use when mobile. Some limits will vary from state to state. However, other restrictions are nationwide.
General Prohibitions in Scanner Use
You are forbidden from using the device to listen to any type of phone call. Manufacturers and individuals are not allowed to sell scanners that can get cellular phone frequencies. US laws also prohibit modification of existing scanners so they can receive cell phone frequencies.
The law also forbids unscrambling encrypted and decoded communication signals. You are not allowed to utilize info from the device for personal gain. For example, a cab driver tunes in to a rival to gather pick up fares info and use them for their advantage.
All states forbid using info heard from the device to aid in the commission of a crime. You cannot reveal the info heard there to other people.
You can only use the device in a vehicle if you are a licensed alarm system contractor, an amateur radio operator or a member of the media on assignment. If you are none of the above, Florida radio scanner laws says you need a written permit from the Chief of Police.
In California, you cannot use the device in the furtherance of a criminal act.
In Indiana, you cannot use them if mobile unless it is handheld.
You cannot use the device when mobile without an FCC license. If they are found in your possession, authorities may destroy them. Exempted are retailers, use in towing truck services, emergency and disaster personnel and media people.
The possession of the device is legal. But it cannot be used for crime furtherance. Felons are forbidden from owning one.
They can be used when mobile only if you are an FCC licensed amateur radio operator or member of the police force. Mobile use is possible with permits from the Superintendant of Bureau of Criminal Apprehension.
The scanner cannot be used in vehicles to block police communications or for personal advantage.
The only limitation is using the device for furtherance of a felony.
You cannot use the device in a vehicle unless you have an FCC
Oklahoma laws forbid its use in the furtherance of felonies.
The law passed in 2002 forbids its use and ownership by convicted criminals. Use when mobile is prohibited too.
The scanner cannot be used by anyone who has been convicted of any crime during the past ten years. This rule applies whether you are convicted in South Dakota or any other state.
Vermont, Virginia and West Virginia
All states forbid using the device for furtherance of a crime.
Keep in mind that radio scanner laws may be subject to change. The rules concerning their use in the US do not apply to other countries. If you live outside the US, you should check the regulations in your area and consult the local authorities.