If your ISP really wants to provide customer&#x2F;household level tracking to advertisers&#x2F;partners, they could easily provide an API to them like getCustomerId(IPAddress, Timestamp).<p>It&#x27;s not entirely clear from the article whether it&#x27;s &quot;Set-Cookie&quot; being injected in to replies, or the &quot;Cookie&quot; header in to requests, or both.<p>Interesting times nonetheless.