MITM attacks. Verizon currently injects tracking headers into HTTP pages. https://www.eff.org/deeplinks/2014/11/verizon-x-uidh https://www.eff.org/deeplinks/20

MITM attacks. Verizon currently injects tracking headers into HTTP pages. https://www.eff.org/deeplinks/2014/11/verizon-x-uidh https://www.eff.org/deeplinks/2014/11/verizon-x-uidh A variety of ISP's (Comcast, MTNL, IDEA) also run MITM attacks and inject ads in pages, sometimes on behalf of law enforcement. I imagine they inject tracking as well. https://blog.ryankearney.com/2013/01/comcast-caught-intercepting-and-altering-your-web-traffic/ https://blog.ryankearney.com/2013/01/comcast-caught-intercep... https://medium.com/@sushubh/delhi-police-is-literally-doing-a-mitm-attack-on-all-mtnl-broadband-subscribers-in-delhi-these-days-e26e4d673e50 https://medium.com/@sushubh/delhi-police-is-literally-doing-... Google could either do these things or block others from doing them.