We're not. Any more than we section people for alcoholism or drug addiction. It doesn't do any good.
When you were spiralling into your addictions, would sectioning you or forxing you into treatment have done you any good? Or would you have gone right back to it the minute you were released?
We don't have limitless resources. There's not much point in throwing effort after foolishness. Like any other addict, these people will change when they hit bottom and want to.
Better bet is to not shame people for drawing healthy boundaries around rage addicts (of all sorts) and don't make it a requirement to have to deal with or serve them at your own expense of being abused. If, like Women, they degrade to the point of having to be put I toncate because they can't care for themselves, then the internet can be taken away and measures can be taken by professionals.
But no. There doesn't need to be a law. The far right needs to start having to live with the consequences of their policies and ideologies more, like the left has had to.