( CNN ) -- Walmart will join the Department of Homeland Security in a program called `` If You See Something , Say Something '' which encourages the American public to take an active role in ensuring the safety and security of the nation , DHS said Monday . `` Homeland security starts with hometown security , and each of us plays a critical role in keeping our country and communities safe , '' Secretary Janet Napolitano said as she thanked Walmart and the more than 320 stores who joined the national campaign Monday . Participating stores , eventually including 588 from 27 states , will play a short video message at select checkout locations to remind shoppers to contact local law enforcement to report suspicious activity , said a DHS statement . `` This partnership will help millions of shoppers across the nation identify and report indicators of terrorism , crime and other threats to law enforcement authorities , '' Napolitano said . The `` If You See Something , Say Something '' campaign was originally implemented by New York City 's Metropolitan Transportation Authority as a simple and effective program that engages the public and key front-line employees to report indicators of terrorism , crime and other threats to authorities , according to the DHS statement . The program has already partnered with the Mall of America , the American Hotel & Lodging Association , Amtrak , the Washington Metropolitan Area Transit Authority , sports and general aviation industries , and other organizations across the country , DHS said .
DHS expands ` `` If You See Something , Say Something '' campaign . `` Homeland security starts with hometown security , '' said DHS chief Janet Napolitano . 588 Walmarts stores joined Monday , Metropolitan Transportation Authority said statement . Program started by New York City 's Metropolitan Transportation Authority .