It also helps that you can text the section you are in and report unruly fans. Security will come and monitor or step in pretty quickly.
Saw this in Buffalo once. Two Buffalo fans bought a giant soft pretzel. Broke a piece off, dipped it in mustard, and threw it 2 or 3 rows in front of them at a fan wearing a Fins jersey. This went on for like 5-10 min. The Miami fan bless his heart just sat there and took it and tried to ignore getting pelted with a soft pretzel in his back. Security was called to the situation. When security came.... they escorted the Miami fan away, who was doing nothing, because they said he was being a distraction and causing an issue being in Fins gear. He was with his friend who was a Bills fan who went crazy (as he should have)....and the 2 fans who were throwing the pretzel at the guy....nothing happened!! They laughed and nothing was said to them. Security looked the other way