This happened a few times at the bank I worked at for almost a decade.
You could count on the technologists to not throw gas on the fire by replying (everyone'd heard of Bedlam DL3), but once non-technical sales, trading and ops were on the list, all bets were off.
Well, aside from the trolling devs. At my company there've been a couple incidents of this where someone jumps on the thread with advice like "Unsubscribe has to be in the title" or "You have to BCC the list!". When that happens... oh dear god.
You could count on the technologists to not throw gas on the fire by replying (everyone'd heard of Bedlam DL3), but once non-technical sales, trading and ops were on the list, all bets were off.