Mon­tana Gov. Greg Gian­forte on Wednes­day signed into law a first-of-its kind bill that makes it ille­gal for Tik­Tok to oper­ate in the state. The law would have much more far-reach­ing effects than bans already in place in near­ly half the states and the U.S. fed­er­al gov­ern­ment that pro­hib­it use of the app on gov­ern­ment devices. The new rules are expect­ed to face legal chal­lenges. And experts say it will be extreme­ly dif­fi­cult to enforce, if not impossible.