Wow. Putting him in jail is like swatting a fly with Mjölnir.

I often wonder what is the right reaction to such a "threat". Is it to ignore the topic until it is carried out (and thus becomes a real crime; someone carrying out something like that is probably a rare thing, despite the FB posts of various previous school shooters)? Will the public tolerate the perceived inaction? Is there something useful that can be done?