Weapons laws and regulations

FILE - In this May 11, 2016, file photo, Tim Foley shows how to climb a section of the border wall separating Mexico and the United States near where it ends as journalists Chitose Nakagawa, right, and Marcie Mieko Kagawa look on in Sasabe, Ariz. Foley, a former construction foreman, founded Arizona Border Recon, a group of armed volunteers who dedicate themselves to border surveillance. With bids due Tuesday, April 4, 2017, on the first border wall design contracts, companies are preparing for the worst if they get the potentially lucrative but controversial job. (AP Photo/Gregory Bull, File)

FILE - In this Sept. 5, 2015, file photo, Arkansas fans cheer on the Hogs during an NCAA college football game against UTEP at Donald W. Reynolds Razorback Stadium in Fayetteville, Ark. The Southeastern Conference said Tuesday, March 28, 2017, it wants Arkansas lawmakers to exempt college sporting events such as football games from a new law greatly expanding where concealed handguns are allowed, citing concerns about safety at its games. (AP Photo/Samantha Baker, File)

FILE - In this Sept. 5, 2015, file photo, Arkansas fans cheer on the Hogs during an NCAA college football game against UTEP at Donald W. Reynolds Razorback Stadium in Fayetteville, Ark. The Southeastern Conference said Tuesday, March 28, 2017, it wants Arkansas lawmakers to exempt college sporting events such as football games from a new law greatly expanding where concealed handguns are allowed, citing concerns about safety at its games. (AP Photo/Samantha Baker, File)

FILE - In this Sept. 5, 2015, file photo, Arkansas fans cheer on the Hogs during an NCAA college football game against UTEP at Donald W. Reynolds Razorback Stadium in Fayetteville, Ark. The Southeastern Conference said Tuesday, March 28, 2017, it wants Arkansas lawmakers to exempt college sporting events such as football games from a new law greatly expanding where concealed handguns are allowed, citing concerns about safety at its games. (AP Photo/Samantha Baker, File)

This Wednesday, March 1, 2017, photo shows an exterior view of the headquarters of Uber in San Francisco. Uber has been wielding a secret weapon to thwart authorities who have been trying to curtail or shut down its ride-hailing service in cities around the world. The program included a feature nicknamed "Greyball" internally that identified regulators who were posing as riders while trying to collect evidence that Uber's service was breaking local laws governing taxis. The New York Times revealed Greyball's existence in a story published Friday, March 3, 2017, based on information provided by four current and former Uber employees. (AP Photo/Eric Risberg)