Oh, college students.They'll use just about anything as an excuse to take off their clothes. We'll give them this one, though, because this bunch of barely-legals is stripping down for a good cause: Raising awareness about the harm coal mining — and coal-powered universities — can do to the environment. The anti-coal undies were designed by organic-clothing designer PACT, and 10 percent of the proceeds goes to helping the Sierra Club find coal-free solutions. The boys and girls gone wild were provided by the Sierra Club Student Coalition. Hey, it works for PETA.