Reading a DNS blocklist

Lorem ipsum dolor sit amet consectetur. A blocklist looks like a list of bad domains and is really a list of somebody's opinions about domains, compiled at a particular moment with a particular tolerance for false positives.

What the lists disagree about

Nullam sed tellus pharetra egestas vitae consectetur.

• Whether a tracker on a site you asked for counts as unwanted.
• Whether a parked domain is malicious or merely useless.
• How long a name stays listed after whatever got it listed stops.

How we merge them

Sed do eiusmod tempor incididunt ut labore. Each list keeps its own identity in the merged set rather than being flattened into one, so a name that only one source objects to can be treated differently from one that all twenty-five do. In the dev console the per-source verdicts show up under sources on the query record, which is the fastest way to work out why something you wanted got stopped.