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Your argument seems to depend on the idea that centralized services are inherently more popular than decentralized services, which isn’t necessarily true. To s

Your argument seems to depend on the idea that centralized services are inherently more popular than decentralized services, which isn’t necessarily true. To say that it’s “much easier” to ban hundreds of IP addresses instead of a dozen IP addresses is ridiculous. It’s no easier to get IP addresses in a distributed system than it is to get them in a centralized system. GMail is a funny example to point to, because email is arguably the most used digital communication method and it’s also decentralized. Try to fully shut down email in the US — where are you going to find a list of all ip addresses hosting SMTP and IMAP servers, and is that going to be easier than just blocking Twitter?

selfhoster11 6y ago
> Where are you going to find a list of all ip addresses hosting SMTP and IMAP servers? Shodan is a readily available database of such data. Just search for all hosts with IMAP, SMTP and POP3 ports exposed and then block those. Alternatively, a DIY scan of the whole IPv4 address range can be accomplished within hours or days. IPv6 address space is harder to scan, but it's arguably safe to ban all such traffic since nearly nothing critical uses IPv6.
- Ekaros 6y ago
  Or even simpler. Just scan all domains for MX records... That information is not even secret, but openly advertised.
  - folmar 6y ago
    MX is not crucial for email, everything falls back to A. I have an email server with no MX in production for years now. Not the most important one, but in use. Edited to add: there is a tiny fraction of providers that would reject the emails from such a setup, but it's really not common and does not include large providers.
oblio 6y ago
In practice centralized services are just more popular. Less hassle to handle them, for users. And email is practically the only decentralized system in widespread use these days. And it's not centralized, but close to it. You shut down 3 or 4 email services, 95% of its traffic is gone.
ajconway 6y ago
It’s easier to ban them selectively, achieving the desired level of censorship. You don’t need to shut down the entire public email network (although it’s possible to do with DPI). You would only need to ban the servers that are involved in spreading of unwanted information.
imtringued 6y ago
I think his point is that you can hide in the "crowd" on a centralized service. In order to find one "perpetrator" you have to inconvenience a large portion of uninvolved people. If there is a decentralized service that is exclusively used by "perpetrators" then banning the service will have a greater impact even if the ban is harder to implement.

selfhoster11 6y ago

> Where are you going to find a list of all ip addresses hosting SMTP and IMAP servers? Shodan is a readily available database of such data. Just search for all hosts with IMAP, SMTP and POP3 ports exposed and then block those. Alternatively, a DIY scan of the whole IPv4 address range can be accomplished within hours or days. IPv6 address space is harder to scan, but it's arguably safe to ban all such traffic since nearly nothing critical uses IPv6.

Ekaros 6y ago
Or even simpler. Just scan all domains for MX records... That information is not even secret, but openly advertised.
- folmar 6y ago
  MX is not crucial for email, everything falls back to A. I have an email server with no MX in production for years now. Not the most important one, but in use. Edited to add: there is a tiny fraction of providers that would reject the emails from such a setup, but it's really not common and does not include large providers.

oblio 6y ago

In practice centralized services are just more popular. Less hassle to handle them, for users. And email is practically the only decentralized system in widespread use these days. And it's not centralized, but close to it. You shut down 3 or 4 email services, 95% of its traffic is gone.

ajconway 6y ago

It’s easier to ban them selectively, achieving the desired level of censorship. You don’t need to shut down the entire public email network (although it’s possible to do with DPI). You would only need to ban the servers that are involved in spreading of unwanted information.

imtringued 6y ago

I think his point is that you can hide in the "crowd" on a centralized service. In order to find one "perpetrator" you have to inconvenience a large portion of uninvolved people. If there is a decentralized service that is exclusively used by "perpetrators" then banning the service will have a greater impact even if the ban is harder to implement.