The sentencing enhancement for distributing child pornography cannot be applied unless a judge finds the defendant knew his computer file-sharing program made the pornography available to others, a federal court held Friday.

Clarifying the standard for a two-level enhancement under the federal sentencing guidelines, the U.S. Court of Appeals for the Second Circuit vacated the sentence of a Vermont man who claimed he didn’t know his “peer-to-peer” or “P2P” software would make files available to other viewers of child pornography.