Viacom president Mel Karmazin has laid down the law to the top execs of 180 Infinity radio stations around America that Viacom owns. Karmazin is said to have told the execs on a conference call that there is a new “zero-tolerance” policy on obscenity over the air: “If you don’t comply, you’ll be fired for cause. This company won’t be a poster child for indecency.”