I'm cocomac on Stack Exchange. Here is my Ask Ubuntu account, which has GitHub linked on it.

Is your feature request related to a problem? Please describe.

I'd like the ability to be able to blacklist a SE user, and have all of their SE per-site accounts get blacklisted as well. There aren't any cases that I know of where a user spams on one site, and is a great user on a different one. Most of the time, if they are spamming/trolling/being rude or abusive, they really should get blacklisted everywhere. I ran into this in recently, where I had to blacklist each of their per-site accounts manually after they were causing trouble on several sites.

Describe the solution you'd like

Having one command to blacklist all of a user's SE accounts (and any that they create in the future, ideally) would be very helpful.

Describe alternatives you've considered

Blacklist the user on each site by hand - slow, tedious

Additional context

There was a conversation in Charcoal HQ:

https://chat.stackexchange.com/transcript/message/60711269#60711269