Once a class has been certified and a constitutional violation has been ascertained, the district court retains broad discretion in fashioning a remedy. Orantes-Hernandez v. Thornburgh, 919 F.2d 549, 558 (9th Cir. 1990). An appeals court must review the terms of the district court's injunction for abuse of discretion. Securities & Exch. Comm'n v. Interlink Data Network, 77 F.3d 1201, 1204 (9th Cir. 1996).