The section deals with acts of VIOLENCE. Words appearing on internet discussion boards are not acts of violence. Sticks and stones break bones; words never cause physical injury and certainly not death.
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“(4) OFFENSES INVOLVING LYNCHING.—Whoever, whether or not acting under color of law, willfully, acting as part of any collection of people, assembled for the purpose and with the intention of committing an act of violence upon any person, causes death to any person, shall be imprisoned for any term of years or for life, fined under this title, or both.”.