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Comment by AshamedCaptain

1 day ago

Well, I appreciate the correction: I meant second level (or whatever is most distinguishing for that TLD). However, even if what you say is true, you really cannot disprove my claim with one nitpick, you need to talk majorities. (And, in case it needs to be said: i really don't think the issue here is distinguishing activity to github.io vs github.com)

Okay, how about this then. Here's some of the IP addresses of posts on the HN front page right now:

  104.21.3.245
  104.21.68.247
  104.21.80.31
  104.21.95.131
  104.21.112.1
  104.26.4.133

None of them have reverse DNS records. Can you tell which is which?

  • So you take literally the worst possible set of IPs (all of them cloudflare), IPv4 only, and yet Copilot (!) is easily able to reverse 50% of them:

      104.21.3.245 -- trebaol.com
      104.21.80.31 -- diwank.space
      104.26.4.133 -- daringfireball.net 
      104.21.112.1 -- simonwillison.net , taras.glek.net
    

    This was literally the worst example you could possibly do. I hope you kept which one was which, I'd like to know if Copilot was right.

    In the meanwhile, from the current top #30 articles on HN (also via copilot script, but I removed non-cloudflare IPs):

      ycombinator.com -- no CDN
      letsbend.de -- no CDN
      grepular.com -- no CDN
      xania.org -- cloudfront
      github.io -- no common CDN
      owlposting.com -- AWS, but IPv4 remained static
      netfort.gr.jp -- no CDN
      simonwillison.net -- cloudflare, 104.21.112.1 fixed
      folklore.org -- azure, 13.107.246.1-255 range
      danq.me -- no CDN
      nature.com -- fastly, IPv4 remained static
      daringfireball.net -- cloudflare, 104.26.4.133
      ssp.sh -- no CDN
      trebaol.com -- cloudflare, 104.21.3.245
      glek.net -- cloudflare, 104.21.112.1
      gov.uk -- AWS, but IPV4 remained static
      phys.org -- no CDN
      diwank.space -- cloudflare, 104.21.80.31 
      free.fr -- no CDN   (my French ISP, btw)
      ericgardner.info -- AWS, but IPv4 remained static
      ghuntley.com -- fastly, IPv4 remained static
      paavo.com -- no CDN
      railway.com -- cloudflare, 104.18.24.53
      alloc.dev -- cloudflare , 188.114.96.2
    

    Look at how many of them are self-hosted, have zero CDN, or otherwise return me always the same IP (even when I try from 3 different ISPs) which makes them trivial to reverse address. This is already a pretty huge success rate and all my context is that you browsed HN first (which I know, see first result on the list). Now imagine the tools a ISP will have at its disposal:

    - IPv6

    - Its Geo region will actually match yours

    - Routing tables

    - The patience to also include resources fetched from these pages in the analysis (i.e. page X always gets its JS from Y domain which results in a constant Z KB transfer).

    - The rest of your browsing activity

    - The rest of everyone's browsing activity including most popular _current_ hosts for each hostname.

    Do you still claim that it is "impossible" to track your activity because of CDNs? I still bet you your ISP can do it with _100%_ accuracy.