Given the power imbalance here, I'm inclined to side with the individual refused entry. MSG can claim whatever they like. They refused access to an event open to the public to someone who was apparently unaware of their policy. It could easily have been that MSG communicated their intent poorly or not at all. It could also be that the law firm ignored them.

What MSG did was petty and doesn't make only them look bad. Given how iconic they are, to me, they make New York City look bad.

I'm not sure I'd ever want to visit MSG. I work for a well known subsidiary of a well know NYC-based company. Who knows, maybe I'll be on the list one day! I see something like this in the news and think I'm not missing much having never been to NYC. Clearly, MSG hasn't thought through the optics of this. Or, if they did, they think they're too big to need to care. I hope they have another think coming.

But unless you are familiar with all the properties of MSG you still don't know which place may or may not allow entry.

If google sends you an email saying you may not use any services provided by google - that's one thing. But what about Youtube? Is that owned by Google or Alphabet? Does Google being upset with you actually mean that all of Alphabet properties are out of bounds?

How much of a business needs to be owned by a corporation before they can ban you from it? 51%? 20%? 5%?

Should you get a letter from each and every business individually?

This is a crazy path to go down that would lead to the fracture of society.

They refused an individual not acting on behalf of their employer though. I'm not sure that notifying their employer is sufficient. If they want to bar an individual acting for themselves, they should have notified the individual.