Also no a lawyer, but... my understanding was that you're always open to legal action from anybody. They might not have a very good case and they might just get

Also no a lawyer, but... my understanding was that you're always open to legal action from anybody. They might not have a very good case and they might just get laughed out of court, but they can still sue you. Is that not the case? Edit: Or I guess as you said in a reply to a sibling comment, you might only count it as "open to legal action" if you have a decent chance of losing.