The equivalent argument would be banning something that makes murder really really easy without much training or willpower. Killing with a knife is hard, and just not very accessible (if you doubt me, try going hunting for deer with a knife instead of a rifle). The equivalent would be some device that made killing really easy, eg something that supported point and shoot. Like, if someone invented a ray gun that you could just point at people and they would die, that would banned really quickly even by the most libertarian governments (because society doesn’t survive very long with them around, or society doesn’t ban them and is just replaced by another society that does).

Lock picks at least take some skill, they aren’t super accessible. But an RF repeater seems to be fairly accessible according to how quickly it spread (although most modern fobs stop transmitting when stationary, so these are only effective for people who carry fobs in their pockets all the time).