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DA 14-1785

December 8, 2014

Enforcement Advisory No. 2014-05



WARNING: Jammer Use is Prohibited

Prohibition Applies to Use by the Public and State and Local Government Agencies,

Including State and Local Law Enforcement Agencies

We again warn the public that it is illegal to use a cell phone jammer or any other type of device that blocks, jams or interferes with authorized communications. This prohibition extends to every entity that does not hold a federal authorization, including state and local law enforcement agencies.

What are "jammers"? Generally, "jammers" -- which include devices commonly called signal blockers, GPS jammers, cell phone jammers, text blockers, etc. -- are illegal radio frequency transmitters that are designed to block, jam, or otherwise interfere with authorized radio communications. Jammers may block cellular communications as well as public safety communications.

Why are jammers prohibited? Jammers do not just weed out noisy or annoying conversations and disable unwanted GPS tracking. Jammers can prevent 9-1-1 and other emergency phone calls made by the public from getting through to first responders or interfere with police and other law enforcement communications that are critical to the carrying out of law enforcement missions. Jammers also prevent the public, including individuals and businesses, from engaging in any of the myriad lawful forms of communications that occur constantly in all corners of the country -- simple one-on-one phone conversations, communication among persons in large groups (such as during lawful rallies and protests), use of GPS-based map applications, social media use, etc.

Although today's smartphones may enable persons to engage in communications that are bothersome to others, this does not provide the right for persons, or even for state or local agencies -- including state and local law enforcement -- to operate jammers. In fact, use of signal jammers by state or local authorities is generally prohibited.

How do jammers work? A jammer can block all radio communications on any device that operates on radio frequencies within its range (i.e., within a certain radius of the jammer) by emitting radio frequency waves that prevent the targeted device from establishing or maintaining a connection. Jamming technology generally does not discriminate between desirable and undesirable communications. For example, jammers can:

* prevent your cell phone from making or receiving calls, text messages, and emails;

* prevent your Wi-Fi enabled device from connecting to the Internet;

* prevent your GPS unit from receiving correct positioning signals; and

* prevent a first responder from locating you in an emergency.




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Illegal to Operate Jammers in the U.S. You may not operate a jammer in the U.S. without express authorization, even on private property. It is illegal to use a jammer on mass transit (e.g., train, bus) or in a residence, vehicle, school, theater, restaurant, or in any other public or private place.

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Operation is Restricted to Authorized Federal Agencies. Federal law provides no exemption for use of a signal jammer by school systems, police departments, or other state and local authorities. Only federal agencies are eligible to apply for and receive authorization.

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Illegal to Import Jammers into the U.S. If you purchase a jammer online and ship it to the U.S., you have violated federal law. When you buy jammers from outside the U.S. -- used or new -- you become the "importer" of an illegal device. It does not matter whether you purchased the device from an established business or an individual selling the jammer in an online auction. Jammers imported from overseas are also subject to seizure at the border.

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Illegal to Sell or Advertise Jammers Online or in Stores. You may not sell or advertise jammers to individuals or businesses on online auction or marketplace sites, in retail stores, or even at your local flea market. Selling even a single jammer is illegal. You also are prohibited from shipping a jammer in the U.S.

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Monetary Penalties Can Exceed $100,000 per violation. Violations of the jamming prohibition can lead to substantial monetary penalties (up to $122,500 for any single act), seizure of the illegal jammer, and criminal sanctions including imprisonment.

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If you are aware of the use of a jammer, please contact the FCC at 1-888-CALL-FCC.

Need more information? Answers to Frequently Asked Questions about cell, GPS, and Wi-Fi jammers are available at

For additional information regarding enforcement of the jamming prohibition, visit or call 1-888-CALL-FCC. To file a complaint, visit [HYPERLINK:] or call 1-888-CALL-FCC.

Media inquiries should be directed tomailto: Neil Grace at (202) 418-0506 or

To request materials in accessible formats for people with disabilities (Braille, large print, electronic files, audio format), send an e-mail to or call the Consumer & Governmental Affairs Bureau at (202) 418-0530 (voice), (202) 418-0432 (TTY). You may also contact the Enforcement Bureau on its TTY line at (202) 418-1148 for further information about this Enforcement Advisory, or the FCC on its TTY line at 1-888-TELL-FCC (1-888-835-5322) for further information about the jamming prohibition.

Issued by: Chief, Enforcement Bureau