A common—and persuasive—argument against gun registration is that those who comply just put themselves on a list to have their firearms stolen by government officials in the future. As if to emphasize the point, the New Zealand government recently confiscated firearms licenses and the guns they covered from 62 people because of their political ideology. The situation is an important reminder that warnings against registering firearms are correct. But it also raises a red flag about governments' willingness to punish people for the ideas they believe. "Sixty-two firearms licence holders with views aligned to the Sovereign Citizens movement had their...