Another problem here is that the legal definitions of the "opt-out" and "opt-in" concepts are different from the way the terms are used by most. Legally, "opt-in" and "opt-out" don't go together: you either adopt an opt-in system, or you adopt an opt-out system, but not both at the same time.
Legally, "opt-out" is the concept where the ball lies in the customer's camp: in order to prevent companies from collecting your personal data, the customer needs to explicitly tell the company. There is no "opt-in" in the opt-out system, as you are automatically "opted-in" to anything they can think of.
"Opt-in", then, is the concept where the ball lies in the company's camp: in order to be able to collect personal data, the company needs to acquire specific permission from the customer. In this concept, there is no "opt out", as you cannot be "opted in" without your permission in the first place.
The US - despite legislative attempts like the Gramm-Leach-Biley Act - is an opt-out society: in order for companies to stop collecting your personal data, you explicitly need to tell them.
To relate this to the Charter case (without knowing what exactly is going on): in an opt-in system, they would have to ask your permission before "installing" the "feature". In the opt-out system of the US, they can "install" the "feature" without your permission, and you have to tell them specifically that you do not want the "feature." Opt-out is shoot-first-ask-questions-later :)
And if you believe that my post makes no sense or is too complicated: wait until you look at the legislative documents :D