Yes, by asking someone who doesn't have permission to give that authorization to do so.
Let's be real, most people are tech illiterate. If someone can't read a contract and there is no one there to explain it to them, then they are not engaging in informed consent.
Of course we have to ask if this is ethical or not. But let's not boil the conversation down to "we asked, so it is right." One side is arguing that the person didn't give informed consent and the other side is arguing that consent was given simply because a button was pressed.
It's honestly an ethical discussion of if this is right or not.
I thought you had to use the information nefariously for there to be a crime.
How can receiving broadcasts be illegal?
Running tools like nmap have gotten people in trouble though, and it varies by country.