Smut on the Internet — and its availability to children — may be a problem that Congress simply can’t do anything to solve without violating the First Amendment rights of adults, a pair of federal appellate judges suggested in oral argument yesterday.

The remarks by Senior U.S. Circuit Judge Leonard I. Garth and U.S. Circuit Judge Theodore A. McKee came during an unusually candid and spirited hour-long argument yesterday in ACLU v. Reno II, the suit filed to challenge the constitutionality of the Child Online Protection Act, or COPA.