If your ISP really wants to provide customer/household level tracking to advertisers/partners, they could easily provide an API to them like getCustomerId(IPAddress, Timestamp).
It's not entirely clear from the article whether it's "Set-Cookie" being injected in to replies, or the "Cookie" header in to requests, or both.
It occurs to me that a mischievous person could easily write a Firefox plugin to (over)write that header with random garbage. If enough people used the plugin, it would render Verizon's data useless.
It's not entirely clear from the article whether it's "Set-Cookie" being injected in to replies, or the "Cookie" header in to requests, or both.
Interesting times nonetheless.