The use of the word "legal" in the title seems charged to me. (EDIT: The edited HN title is better now, thanks).
Especially given, from the article:
> In the United States, there are no federal laws that restrict the use of facial recognition.
Especially given, from the article:
> In the United States, there are no federal laws that restrict the use of facial recognition.
My experience is that most Americans think their privacy is protected; that deploying facial recognition software on them would be illegal. It's not. They're stating it so to overcome the public misconception.
If you're instead talking about ethics and morals, thats an entirely different discussion.
So if there's no laws saying you can't do it, it's legal.
But, I'd argue the use of "legal" was to make a real point: We assume this isn't legally possible today, and the article is showing how it is. So I'm not saying you're wrong, simply that I disagree.