resolve: remove the fallback dns server list
DNS questions (which necessarilly include IP addresses) are personally
indentifying information in the sense of GDPR
(https://gdpr.eu/eu-gdpr-personal-data/ explicitly lists IP address as
PII). Sending those packets to Google or Cloudflare is "forwarding"
this PII to them. GDPR says that information which is not enough to
identify individuals still needs to be protected because it may be
combined with other information or processed with improved technology
later. So even though the information in DNS alone it not very big, it
may be interpreted as protected information in various scenarios.
When Fedora is installed by an end-user, they must have the reasonable
expectation that Fedora will contant Fedora servers for updates and
status checks and such. But the case of DNS packets is different,
because the dns servers are not under our control. While most of the
time the information leak through DNS is negligible, we can't rule out
scenarios where it could be considered more important.
Another thing to consider is that ISP and other local internet access
mechanisms are probably worse overall for privacy compared to google and
cloudflare dns servers. Nevertheless, they are more obvious to users and
fit better in the regulatory framework, because there are local laws
that govern them and implicitic or explicit agreements for their use.
Whereas US-based servers are foreign and are covered by different rules.
The fallback DNS servers don't matter most of the time because
NetworkManager will include the servers from a DHCP lease. So
hopefully users will not see any effect from the change done in this
patch. Right now I think it is better to avoid the legal and privacy
risk. If it turns out this change causes noticable problems, we might
want to reconsider. In particular we could use the fallback servers
only in containers and such which are not "personal" machines and there
is no particular person attached to them.
https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/3C4KESHIMZDB6XCFO4EOBEDV4Q2AVVQ5/
I think we could provide a default dns server list more reasonably if
there was some kind of privacy policy published by Fedora and users
could at least learn about those defaults. Sadly, we don't have any
relevant privacy policy (https://pagure.io/Fedora-Council/tickets/issue/53).