A professor says he has developed long-range iris scanning, which means cameras could recognize everyone who walks down the street.

Iris scanning can help governments imprison whistleblowers, which can enable governments to get away with killing thousands or hundreds of thousands, but he thinks he's going to "save a life". Well-meaning but sad.

The professor makes a calculatedly ambiguous statement that "people" are being tracked in other ways. Indeed, many people carry portable phones and pay with credit cards, so they are tracked in other ways. Many people, but not all!

Some of us protect our privacy by refusing to do those things. It is still possible to do this. Many people do this, part of the time.

If his statement is criticized, he can claim that he didn't say "absolutely all people". He only said "people", which means "some people". Strictly speaking, that statement is true -- but it fails to support his conclusion. This gap makes his argument false.

It is true that people are under strong pressure to do those foolish things. Due to that pressure, we cannot dismiss the harm of those practices by saying "They do those things voluntarily". We need to take that pressure off people in general. But at the same time, it is also false to argue that "Everyone does them, so further surveillance does people no harm." That's equivalent to, "He has cancer, so if we give him pneumonia on top of that, that will do him no harm."

Can we develop technology to protect ourselves from iris scanning?