matrix-chat: remove/ban external user from public matrix rooms
Recently there appeared a bit of spam via Matrix on stadtgestalten.org. The spam bot did not create a grouprise account, but just joined two (or more?) public rooms and emitted a message.
It would be nice, if we could remove such users from all matrix rooms, which were populated (and are administered) by grouprise's matrix-chat
bot.
This could be an administration command, as well as a grouprise-commander bot command.
We need to decide, whether "remove" or "ban" would be the appropriate reaction. Probably "ban" is the way to go.