Comment by jeroenhd

3 years ago

There's more to it than just anti-fingerprinting. There's also some other fingerprinting going on, and I think there may be some kind of IP reputation system that influences these prompts as well. I've put privacy protections up to max but never see Cloudflare prompts.

I see them using some VPNs and using Tor, but that makes sense, because that's super close to the type of traffic that these filters were designed to block.

I suspect people behind CGNAT and other such technologies may be flagged as bots because one of their peers is tainting their IP address' reputation, or maybe something else is going on on a network level (i.e. the ISP doesn't filter traffic properly and botnets are spoofing source IPs from within the ISPs network?).

Every IPv6 thread we get someone saying "Oh v6 is worthless, we can stay on v4 forever, there are no downsides to CGNAT". I still have no idea how they can think that.

  • Those responses baffle me. I don't think most of those have ever been on the receiving end of anti-abuse features targeting shared IP addresses. I wonder if they're the same people who consider IPv4 a scarce resource that needs to be shared carefully.

    Try ten Google dorks for finding open Apache directory listings; your IP address gets reCAPTCHA prompts for every single search query for minutes. Share that IP address with thousands of people, and suddenly thousands of people get random Google/Cloudflare prompts.

    • Yeah, ever try to use Google through Tor? If you're lucky, it will let you do a captcha and get your result, but mostly it just says the IP is temporarily blocked for abuse.

    • IPv6 addresses are effectively the same as shared IPv4 addresses in anti-abuse systems. All anti abuse systems treat a /48 or /56 level the same as a single IPv4 address. It's the only way to actually detect one system doing abuse.

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  • You get with v6 it's all disposable? You can use it for 1 min and throw it away.

    You'll be able to to get them from any geo-location easy as pie.

    So it's worse. You'll be even less trustworthy unless you register as trustworthy and keep it, which means tracking. The same as having a fingerprint or login now.

    As pro argument that sucks, it's the opposite.

    • The second half of the address is disposable, plus a few more bits. The first 56 bits or so are allocated just like non-CGNAT IPv4 addresses are currently allocated.

    • So then you can build up a good reputation by sticking with one IPv6 address, and you shouldn't have to deal with any silly bot restrictions at all.

>I suspect people behind CGNAT and other such technologies may be flagged as bots because one of their peers is tainting their IP address' reputation, or maybe something else is going on on a network level

This is a thing that is absolutely happening, I got temporarily shadowbanned for spam on Reddit the day I switched to T-Mobile Home Internet which is CGNAT'd, and I didn't post a single thing

I'm curious why you seem to think that Tor is more legitimate to block than those behind CGNAT. There's been plenty of research showing on a per-connection basis, Tor is no more prone to malicious activity than connections from random IPs, and that it's only on a per-IP basis malicious activity is more likely. I.e., it's the same phenomenon as why CGNAT causes collateral damage. You could argue that Tor is opt-in and therefore less worthy of protection, but saying "users who want extra privacy deserve to be blocked, even when we know (as much as one can know) that they're not using it for malicious reasons" seems like a fairly dystopian premise.

I'm actually kind of glad more people are becoming aware of this problem, and hope it finally spurs more interest in mechanisms that divorce network identity from IP addresses -- including the work Cloudflare is doing on Privacy Pass!

  • In my opinion Tor is as good a privacy-preserving technology as VPNs and should be treated very similarly. I use Tor sometimes and I'm annoyed as you are with all the CAPTCHAs and outright blocks when I just want to read an article on a website.

    However, the sad fact is that Tor is abused for a LOT of malicious traffic, much more so than any VPN provider, let alone normal ISPs using CGNAT. The anonymity combined with its free nature make it very attractive for bad people to use Tor for bad things without any reasonable fear of getting caught.

    An outright block for Tor traffic is definitely out of the question, but adding CAPTCHAs to sensitive things (like account signups, expensive queries, etc.) is sadly a requirement these days.

    Blocking exit nodes does nothing to protect your website's security, but it sure as hell cleans up the logs and false positives in your security logs. It's not just Tor, though, there are also some home ISP networks that don't seem to care about the botnets operating inside their network.

  • "I'm curious why you seem to think that Tor is more legitimate to block than those behind CGNAT."

    Who said that? I don't see anyone saying that.

    • How else would you interpret "I see them using some VPNs and using Tor, but that makes sense, because that's super close to the type of traffic that these filters were designed to block"? They seem to be implying that Tor is a form of acceptable collateral damage, but the likely problem here, i.e. the CGNAT instantiation of collateral blocking, is not.

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Some sites I have already visited keep popping them up. And I'm on public IP that should have been associated with my computer for a while...

Maybe it is just per use case. Or they think I'm a bot as I keep looking at sites every couple hours... Which might be actually common with these sites.