Jon Hammar, an Afghanistan and Iraq veteran and former U.S. Marine, was arrested in Mexico on Aug. 13 and remains there today, reportedly chained to a bed for much of the day. A recent story by the McClatchy news service has shed light on Hammar’s situation, and now concerned Americans are using the hashtags #BringHammarHome and #FreeHammar to draw attention to his case.

Hammar, 27, was arrested for possessing a 60-year-old Sears & Roebuck shotgun. Mexican authorities found the disassembled shotgun in Hammar’s motor home as he and a friend crossed the border on a surfing trip and charged him with possession of a weapon restricted for use to Mexico’s armed forces.

Needless to say, Americans are demanding action.

Hammar’s sister Katie has started a petition on the White House website.