Russell Jackson has a great post on class action litigation on behalf of uninjured plaintiffs, his example at hand being a California lawsuit on behalf of a class of patients not hurt by Lasik surgery (via Beck & Herrmann). It seems the surgery had gone on with the use of a laser tool that had not yet been approved for that use by the Food and Drug Administration, though it subsequently was. In order to sidestep individualities that might defeat class treatment, the class was defined specifically to include only persons who were entirely unharmed by the successful surgery, and merely, you know, wanted money on the principle of it all.