You could also say it's like going to a large apartment building and ringing all the doorbells to see who's there. And (depending on the nmap flags we're talking about) then profiling their voice on the intercom to figure out what kind of people live in each apartment.
Perhaps. Ought that be illegal?
> Perhaps. Ought that be illegal?
I can't really explain why but I think there is a difference between doing something manually and automating it. For example, it is perfectly ok for a police officer to sit behind the bushes in front of someone's front porch with a pair of binoculars but not ok to put a hidden camera 24/7 in front of everyone's front porch.
By whom? I disagree; using nmap is more akin to, say, standing outside a building (on public property) and taking (or painting) a picture of the building. Yes, some people have gotten in trouble for that. Should they, though?