Madison Square Garden's surveillance banned this fan over his T-shirt design

The legal disclaimer shown at the venue implies that the biometrics are collected (and “retained, stored, and converted”) at the venue. That’s clearly only half of the story. They must also be collecting (and retaining, storing, and converting) information about anyone using sources outside the venue.

The implication from chronology of the story is that MSG must have done something like googled Miller, found his LinkedIn bio-pic, and put that in their “safety and security” database?

I think we can conclude therefore that the disclaimer sign is not a quasi-legal disclaimer to let the venue record your face, but in fact a canard to divert your attention from the fact that they have already created records linking your face to your name — records created without your consent and without letting you know they did it.

You could probably argue a legitimate interest if you're collecting face recognition data on proven hooligans, but scraping pictures of people that have not been to your venue off a website clearly isn't a legitimate interest for such privacy invasion.