Long back when this started, OpenDNS was the largest public DNS provider. And I know at one point they started "hijacking" google requests - you can read this h

Long back when this started, OpenDNS was the largest public DNS provider. And I know at one point they started "hijacking" google requests - you can read this here : http://www.dslreports.com/forum/r21284386-Google-Com-Hijacked-by-OpenDNS http://www.dslreports.com/forum/r21284386-Google-Com-Hijacke.... This was in 2008. They used to also hijack DNS requests to show their own ads. And i am pretty sure many ISPs always played around with DNS in this way. In 2009, Google launched its own Public DNS - the reasons given were to make the web faster and safer, and i think there is some sense in which they have delivered. But I think another reason was defensive - provide an alternative to OpenDNS and to crappy ISP DNSs. In 2014 - OpenDNS stopped using DNS to show ads : https://umbrella.cisco.com/blog/2014/05/29/no-more-ads/ https://umbrella.cisco.com/blog/2014/05/29/no-more-ads/.