A class action has been brought to enjoin the City of Indianapolis from setting up roadblocks to catch drug offenders, a practice that the plaintiffs claim violates the Fourth Amendment. The plaintiffs motion for a preliminary injunction was denied on the ground that the Citys practice is lawful, precipitating this interlocutory appeal under 28 U.S.C. sec. 1292(a)(1). The legality of drug roadblocks has divided the other courts that have been asked to decide the issue. Compare United States v. Huguenin, 154 F.3d 547, 554-55 (6th Cir. 1998); United States v. Morales-Zamora, 974 F.2d 149 (10th Cir. 1992); Galberth v. United States, 590 A.2d 990 (D.C. 1991), and Wilson v. Commonwealth, 509 S.E.2d 540 (Va. App. 1999), which held them illegal, with Merrett v. Moore, 58 F.3d 1547 (11th Cir. 1995), and State v. Damask, 936 S.W.2d 565 (Mo. 1996), which held them legal. This is our first case. Because it was decided by the district court on a very skimpy stipulation of facts, our ruling on the legality of the Citys program is necessarily tentative.