Answer:
obscene
Explanation:
Note that in the case of ┬аRoth v. United States the U.S. Supreme Court allows banning of any material that tended to "deprave and corrupt those whose minds are open to such immoral influences", and was ┬аconsidered "obscene" material.
This ruling led to the conviction of Samuel Roth, because he was sending "obscene or filthy" materials through the mail for advertising purposes.