People post videos of others in public all the time, do you think they ask every single person on YouTube to sign a consent waiver to be filmed? There's no "gotcha" as you're implying, those are all things people do already without creepiness.
This is ok to you? You’re a creep. Maybe you’re the guy in this article
Voyeurism is an actual crime compared to what restaurants in this thread are doing. Don't create a false equivalence where there is none.
What if the restaurant followed you with a drone and took pictures of everything you ate in public for a month?
Is that not also voyeurism? There is a difference between the real world and online, to most normal people, hence my initial comment saying generally only HNers seem to equate the two.