§ 1391 Additional security.

If a court has ordered an injunction against you, you have the right to ask the judge for more security (money or a bond) to protect you in case the injunction turns out to be wrong. You can make this request at any point before the case is decided, but you have to give the other side reasonable notice before you ask.

The judge will look at the security that's already in place. If the person who backed the injunction has moved out of state, or if their financial backing isn't strong enough anymore, the judge can step in. In that case, the judge can cancel the injunction entirely, unless the other side comes up with better security within a reasonable amount of time.

This rule exists to protect you if you're the one facing an injunction. It makes sure there's always someone financially responsible standing behind the order, so if the injunction ends up causing you harm and shouldn't have been granted, there's money available to cover your losses.