Perhaps a rule from the Institution, put in the personal conduct manual.
- Any student who enters upon the basketball court during a game or within 15 minutes of the conclusion of a game while basketball players are still present, without express permission from the school, shall be 1) Expelled, or 2) suspended, or 3) fined up to $5,000, or4) any combination of the above.
Or a Kansas law prescribing the same punishment as one might get if someone hops the fence at Royals Stadium.
If it were something that the powers that be wanted to stop, you can create stiff penalties. Run the announcement before the game, at halftime, and in the last five minutes. This would stop the flood of students, but still not the few idiots that are drunk or that penalties don't persuade.
Not sure I see it as a real problem yet.