(Andrea Bernstein, Transportation Nation, May 14) In San Francisco, writes KALW's Nathaneal Johnson, paying the transit fare is sometimes seen as a voluntary act. But the transit system is losing $19 million a year -- and is stepping up enforcement. Johnson takes a ride with a MUNI "cop". Meanwhile, in Paris, farebeaters have a taken a different tack. Instead of paying the fare, they're contributing to a fund for those caught not paying.