From Jones v. United States, this interesting exchange where Kagan alludes to London’s omniveillance:

JUSTICE KAGAN: What is the difference really? I’m told — maybe this is wrong, but I’m told that if somebody goes to London, almost every place that person goes there is a camera taking pictures, so that the police can put together snapshots of where everybody is all the time. So why is this different from that.

MR. LECKAR: It’s pretty scary. I wouldn’t want to live in London under those circumstances.

JUSTICE SCALIA: Well, it must be unconstitutional if it’s scary.

(Laughter.)

JUSTICE SCALIA: I mean, what is it, the scary provision of what article?

JUSTICE BREYER: And in fact, those cameras in London actually enabled them, if you watched them, I got the impression, to track the bomber who was going to blow up the airport in Glasgow and to stop him before he did. So there are many people who will say that that kind of surveillance is worthwhile, and there are others like you who will say, no, that’s a bad thing. But that isn’t the issue exactly in front of us.