It seems like every year, I have at least one fan who thinks their $4 allows them to sit in the front row and yell at the officials.
My favorite is when we go to a private christian school playing another private christian school and get yelled at for 4 quarters. Its all respectful when the anthem and prayer are being said, but throw that ball up in the air and the devil takes over.
In most of the gyms I work, the game administrator has always been helpful. I usually ask them to work with the fan so they can stick around to watch the game. I try to give the benefit of the doubt. A few years ago we had a guy sitting first row at half court, about 45 years old with his hat on backwards. He had something to say after every call. The administrator went over and said, "you can keep your comments quiet and stay, pay me an extra $100 so I can get another official, or leave the gym." The guy left at half time and watch the game from the windows outside.