Until it gets accidentally turned on by a browser update, or by some rogue plugin (wouldn't put it past Adobe actually), or by an optional Windows Update, or by

Until it gets accidentally turned on by a browser update, or by some rogue plugin (wouldn't put it past Adobe actually), or by an optional Windows Update, or by some grayware that I mindlessly install on a computer. If it's off by default, it should be in a plugin. If you want it, come and get it.