You must get their consent. T-shirts say lots of things that are hyperbole or bluster. Like "official boob inspector" is not generally understood to mean that you're announcing you literally are a licensed doctor.
The article cites law, like with recent court cases. Let me add the exact court case they cite:
The law only applies to secret recordings, however, so affirmative consent is not necessary when all parties are aware of the recording.
Curtatone v. Barstool Sports, Inc., 169 N.E.3d 480, 483 (Mass. 2021).
I am not trying to inform others of recording, actually, by my T-shirt sign. I trying to protect myself against the wrong law. If I was a lawmaker I would probably make all recording in public spaces legal. But if use of recording inflicts harm on you - you should be allowed to sue for damages. Probably you are already allowed anyway.
Again: a harmful use of recording without concent or notification should be punished, not the recording itself. I think.
You must get their consent. T-shirts say lots of things that are hyperbole or bluster. Like "official boob inspector" is not generally understood to mean that you're announcing you literally are a licensed doctor.