*"... (and a lot you don't, but are referenced on the pages you view: images, scripts, things like that). That's why some people tell you to use a VPN to protect your privacy against your ISP. But using DNS-over-TLS or DNS-over-HTTPS is enough." Can you please explain the DNS thing to me in layman terms, if it is possible? Does having DNS over HTTPS hide the website I visit from my ISP. Is that what you mean? Thanks for your answer!

I was just writing exactly the same points, but you might have worded it even better. The last paragraph is the most important: with both cellular and wired connection they know your exact location. There have been some historical systems like packet radio networks where the location information is less accurate, but let's face it: they are not quite practical for watching videos on YouTube or PornHub.

Knowing the sites aren't just about the DNS, and DNS isn't even the best way to analyze or monitor this, as the results are cached. In practice, it's SNI (RFC 6066, 3) that reveals this information. Luckily, Encrypted Client Hello (ECH) is on its way: draft-ietf-tls-esni-08.

@EsaJokinen I can see Google thinks I live in city A, whereas I actually live in a neighboring city B. Is this the "precise location" you are talking about? Your coordination will be greatly appreciated. Thanks

@EsaJokinen ...... but let's face it: they are not quite practical for watching videos on YouTube or PornHub." What do you mean by this? They are not practical for the ISP to find out the actual content, is this right?

Packet radio is not practical for video streaming because of the low bandwidth. Satellite Internet is a bit costly for that. And Google "thinking" something refers to public GeoIP data, which isn't accurate. Your ISP isn't limited to that, as it has your exact address, as explained in the answer.

Packet radio bandwidth is on the range of a handful kbits/second... Don't expect to watch even 144p videos in realtime.

Relevant XKCD

@ThoriumBR What is that link?

What about security.stackexchange.com/questions/155057/…

@ThoriumBR But this question's answerers clearly say that virtually it is absolutely possible for ISPs to determine which video one sees. Both answerers agree that it is almost 100% possible to accurately predict what video was seen. What do you want to say about it?

On a site with a hundred videos? Possible. On a large site like PornHub, Youtube, Vimeo, DailyMotion? Impossible.

@Jay Shah - The referenced link while technically accurate is disingenuous. What he's saying is that if he visited the same page that you did and kept records of the traffic patterns for that page, he can compare the encrypted traffic patterns and likely identify the page match. That requires a priori knowledge of the page traffic and does not scale well. In essence it's a parlor trick.

@ThoriumBR But the answerers clearly site 3-4 research papers where it was shown how researchers accurately predicted which movie on Netflix was being watched. Netflix is a BIG site. How did they do that?

Lots of resources, a team of dedicated researchers, a lab environment, and ONE client. Not a large site with hundreds of thousands of watchers on the real world.

@ThoriumBR I value that you spend your time answering my follow-up questions:) Thanks. May I please ask for a last opinion of yours? Islamic countries are strictly against homosexual content. One of my homosexual friends ranted about their "unlucky" birth in Indonesia. It's very strict, you know. How about the Government ordering ISPs to find out what videos were being watched by citizens, using this method? How about investigating citizens activities on homosexual websites? How about citizens activity on anti-Islamic websites? They really want to catch these people. Your say on this proposal?

I am essentially asking about the feasibility, nothing else. I have some concerned Muslim friends who are so worried on this that one day some Government official would come to their residence with evidence of their activity obtained from ISP (by the research paper method) to arrest them.

There is a second question, is there any chance ISPs eventually dispose off encrypted data? Like after 6 months or 1 year? Why would they really store encrypted data? If they do not keep encrypted data for much time, it would be a big sigh of relief for my Muslim friends. Thank you for your help.

When you realize how much storage it takes to store 6 months of HD video, encrypted, you will see how an ISP would run out of business pretty fast if they wanted to store that. Storing encrypted emails is one thing, storing HD video? Not happening...

@ThoriumBR So there is no chance Indonesian Govt can ask ISPs to find out who watched a homosexual video on a particular https website because ISPs simply don't keep encrypted browsing histories of people. Is this rightly stated?

you may want to check out how Kazakhstan does it: bugzilla.mozilla.org/show_bug.cgi?id=1567114

How Kazakhstan did tried. It required users to install a third party Root Certificate, and users could deny the installation. The attempt failed, of course...

@JayShah As others have said, it is pretty unlikely that the ISP could do anything here, unless sites are doing something dumb like requesting from different domains for each video, but that said, there is no harm in suggesting your friend uses a reputable VPN based in country with a good track record for human rights though, to take the ISP out of the equation.

@pcalkins Thank you for the example, and thank you ThoriumBR for commenting. One user in my other related question mentions "...government agencies often have interfaces to the ISP or to internet exchanges which allows them to copy selected traffic to their own systems.". --- What sort of traffic would govt agencies (law enforcement) be interested in selecting to copy to the interface? Can it include Homosexual material?

@Jack Thank you for your opinion:)

I would assume they collect everything, but they only look at certain people. This would be classified and protected by any guv'ment who collects it. They wouldn't throw stones that could also be thrown at them. So I think you're safe in this particular case. Probably depends on whether you've been labeled an "enemy of the state" and how tyrannical the guv'ment is. In any case, there will be politicians in your system who are also gay and would want to protect that information so the pool of people under surveilance would be smaller than "all gays". (IMO)

I am not aware of any ISP recording everything. Recording metadata is one thing (possible, plausible, doable, done all over the world), recording everything is out of the capabilities of any ISP. Small ones don't have money for that, large ones have way too much traffic...

Yes ThoriumBR ISPs can't store that much data (as you previously said), and yes @pcalkins, I was talking about such a data storage center you describe. But apart from ISPs and such data centers, does GOOGLE store data that associates browsing activity with the IP address that was assigned at the time to a device? If I see a video on Vimeo (using Chrome browser and Google search engine), will Google have a record of which IP address saw which video on Vimeo?

Asked a Quora question too, but have received no answers. My friend is afraid of asking all this himself, so I am doing it in their behalf.

Well, some passerby has answered it casually right now, but it is simply a casual one.