As lawmakers, technology companies, and media outlets try to come up with more restraints on “extremists,” it’s important to keep an eye on whom they include under that label.

You might think, when a journalist, tech mogul, or politician says “extremist” speech needs to be reined in or we need more federal surveillance of extremists, that they are talking about neo-Nazis or coup-plotters. We know, though, that “extremist” has long been expanded to include anyone with fringe beliefs, such as polygamists or RFK-style anti-vaxxers. Also, “anti-vaxxer” has been expanded beyond its old meaning, which involved rejection of all vaccines, to now include anyone who doesn’t want the COVID vaccines.