U.S. appeals court strikes down ban on bump stocksJan 6 (Reuters) - A U.S. appeals court on Friday struck down a rule the Trump administration had adopted following a 2017 Las Vegas mass shooting that banned "bump stocks," devices that allow people to rapidly fire multiple rounds from semi-automatic guns.While the federal Bureau of Alcohol, Tobacco, Firearms (ATF) and Explosives had interpreted a law banning machineguns as extending to bump stocks, U.S.Circuit Judge Jennifer Walker Elrod said the law did not unambiguously prohibit them.Elrod, writing for the majority, said the law also did not give "fair warning that possession of a non-mechanical bump stock is a crime.""The resulting circuit split should bring this decision to the U.S. Supreme Court's attention promptly and supply a suitable vehicle for deciding this issue once and for all," said Mark Chenoweth, the president of the New Civil Liberties Alliance, a conservative group that litigated the case."