From Guns.com:

A local news station reported that the “Come and Take It” rally, which was organized by Don’t Comply, was part of a response generated after Army Master Sgt. CJ Grisham was arrested in March for “rudely displaying” his AR-15. While it is legal to open carry long arms in Texas, apparently a concerned citizen called when she saw the man carrying the weapon while on a Boy Scout hike with his son in the rural community.