Last year, I had a situation where some fans on the front row, opposite table were running their mouths at me and the visitors. Just before a throw-in, I had had enough. Quietly, I said to the ringleader, "If you don't shut your trap, I'm gonaa have you thrown out of here."
They calmed down until about a minute to go. But the ringleader figured this late in the game, I would just ignore him. Wrong answer. I don't remember what he said, but it was during a dead ball. I blew my whislte and waved the deputy sheriff over. With him came the principal. See ya!
After the game, the principal thanked me and assured me that the guy wouldn't me back for 365 days.