Apparentley obscenity isn't protected in the constitution...
"Obscenity and Prior Restraint .--Only in the obscenity area has there emerged a substantial consideration of the doctrine of prior restraint and the doctrine's use there may be based upon the proposition that obscenity is not a protected form of expression"
http://caselaw.lp.findlaw.com/data/c...nt01/09.html#3