From:
Massachusetts General Laws Chapter 272. CRIMES AGAINST CHASTITY, MORALITY, DECENCY AND GOOD ORDER.
Chapter 272: Section 36A. Sporting events; penalty for abuse of participants and officials.
Section 36A. Whoever, having arrived at the age of sixteen years, directs any profane, obscene or impure language or slanderous statement at a participant or an official in a sporting event, shall be punished by a fine of not more than fifty dollars.

Maybe the threat of a $50 fine will keep the really abusive people quiet!
Maybe a sign, conspicuously posted the entrance to each tournament, quoting this law, and saying "Violators will be silenced"

Happy New Year!
Gene