As the years pass, I keep thinking back and realize that Richard Stallman was right all along:
> For personal reasons, I do not browse the web from my computer. (I also have not net connection much of the time.) To look at page I send mail to a demon which runs wget and mails the page back to me. It is very efficient use of my time, but it is slow in real time.
I think Stallman just shot himself in the foot by even revealing that much. Unless a lot of people do the same thing, it's very easy to conclude that it was Richard Stallman who sent that WGET request, granted a few variables. The difficult part is perhaps tracking it back to its actual source, but I don't think Stallman is that hard to find. All this is of course extremely chilling. I'm sure a profile could be built up around WGET requests, and then employing some "likelihood machine" on it, to make educated guesses as to how likely it is that the WGET request was actually from Richard Stallman. I think we've just stumbled upon a new and "fun" Where's Wally game here!
I actually did exactly that a while ago. Where I worked, we didn't have internet access but we had email access, so as a workaround, I made an email server on my home machine that fetched web pages for me. A coworker took it even further and made a proxy server that automated the process so you could actually browse the web, although very slowly. Just to say that Stallman is not the only one with this idea.
It was in the early 2000, and smartphones weren't a thing. It also was a time where companies were paranoid into letting employees access the internet, but at the same time had abysmal security. By that I mean viruses ran free on shared folders, undetected because their antivirus software was years outdated. Very different times...
In Germany there is a "WhatsApp" SIM [1], where you have to pay for normal internet use, but WhatsApp texts are free of charge.
With a technique which you described, you could probably abuse a phone with this SIM as a "free" hot spot with infinite data.
A lot of paid Wi-Fi hotspots allow DNS traffic through unmolested, that's a similar loophole