We've long had such labs researching dangerous bio stuff primarily, if not entirely, for defending against the possibility someone or nation would use biological warfare. It's really a double-edged sword. Don't do the research and somebody releases a horribly nasty bioweapon on us we can't defeat, or we research really nasty bioweapons to know how to stop something like that but at the same time know how to release one.
It really makes nuclear weapons look almost benign and sane.