Via this How Appealing link, in the case of Swiecicki v. Delgado, the Sixth Circuit reversed the dismissal of a civil rights suit brought by a man who after heckling the Indians at Jacobs Field was booted from the stadium, wrestled to the ground, and arrested for disorderly conduct. The District Court had granted summary judgment to the security guard defendant on various grounds, including the statute of limitations, whether the defendant was a state actor, and qualified immunity.
The ruling on state action might be affected by this Supreme Court filing described on the SCOTUSblog, about another security guard case.
The opinion concludes: "For a baseball fan to make a “federal case” out of being ejected from a game may well strike many as a colossal waste of judicial resources. A jury might well agree. But this is the type of case where the ultimate result is totally dependent on whose version of the facts one believes. Under these circumstances, the grant of summary judgment to the police officer on the basis of qualified immunity is inappropriate."
I guess that's the difference between the major leagues and the minor leagues. In Judge Williams' famous opinion in Simmons v. Baltimore Orioles, 712 F. Supp. 79 (W.D. Va. 1989), the heckler got his in the parking lot after the game at the hands of the player he'd been heckling, and then sued everyone from the parent club on down.