CARIAD is a "day one" denylist for new admins. We scan a range of high-volume servers and monitor what domain blocks they agree on. Spoiler, it's not much.
Only one domain is blocked by all major providers, and a little over 100 are blocked by more than half.
After manual review we add them to the database for aggregation and construct a very basic denylist alongside our DNI list, using standard labels.
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