It's a free service. Unless your company forces it to use it, OpenDNS is opt-in. As I said, it makes people mad because ISPs effectively force you to use their

It's a free service. Unless your company forces it to use it, OpenDNS is opt-in. As I said, it makes people mad because ISPs effectively force you to use their DNS, and some use it to serve ads. Nobody complains about Google serving ads on their pages, but if your ISP inserted ads through some kind of MITM, it would make people pretty angry.