[pests]

Your example sounds like what people do in person all the time.

My local barber knows me when I walk in. He knows what I look like, what I wear, what I usually order.

He uses this to make my experience better. He saves me from having to tell him what I want, he knows what seat I like to sit in, and so on.

I don't have to tell him I'm coming in. He can figure it out by looking at me walking in the door.

[DeathArrow]

You can even tell who you speak with by recognizing the caller's voice, without seeing him.

You can recognize a writer by his style.

What GP is trying to say it's ok for people to use pattern matching but it's immoral if they use machines to do pattern matching.

[pests]

But why?

[tightbookkeeper]

> by looking at me

Your presented person is very different from an amalgamation of clues which are not meant to disclose public information and are not you.

But this is easy to solve. Instead of rationalizing call up a customer and try it.