(c) Security. The court may issue a preliminary injunction or a temporary restraining order only if the movant gives security in an amount that the court considers proper to pay the costs and damages sustained by any party found to have been wrongfully enjoined or restrained. The United States, its officers, and its agencies are not required to give security.
It isn't necessary for the US to give security, but it should pay damages. If the EPA passes regulation X, a corporation asks for a preliminary injunction and fails, but either (a) appeals and does get the preliminary injunction or (b) gets a permanent injunction after a trial, then does the corporation get money damages for the period it complied with regulation X? It should.
From Rule 65:
(c) Security. The court may issue a preliminary injunction or a temporary restraining order only if the movant gives security in an amount that the court considers proper to pay the costs and damages sustained by any party found to have been wrongfully enjoined or restrained. The United States, its officers, and its agencies are not required to give security.
It isn't necessary for the US to give security, but it should pay damages. If the EPA passes regulation X, a corporation asks for a preliminary injunction and fails, but either (a) appeals and does get the preliminary injunction or (b) gets a permanent injunction after a trial, then does the corporation get money damages for the period it complied with regulation X? It should.