I went to a WebGL test page that warned it might crash your machine by drawing lots of polygons. Boy it wasn’t kidding. Locked up Chrome, locked up the Mac graphical shell. I could log in via ssh and the machine was fine, not even anything spinning CPU, but couldn’t kill the Chrome processes. kill -9 did nothing. So then I rebooted. It didn’t reboot either, the best MacOS could do was to shut down sshd so I couldn’t even log into my machine.