"Go ahead, monitor my calls."
Please don't say that.
I see this as the third step in the slippery slope to corporate Big Brotherdom. (Tivo was the first. Gmail is the second.)
The argument that is free and can be ignored is very weak. As Saletan noted, expectations of privacy change. So do expectations of value.
Back to phone filters. What if Worldcom rose from the dead to offer free cellular service for anyone willing to sign up for such an "Ads with ears" program? Carriers would love it because they have the advertisers covering their operating costs. It's unobtrusive, right?
Would you sign up if they offered an i-Phone? I'd bet 98% of the population would sign a deal like that. Don't like it? Carriers can keep sweetening the deal with music, games, and technology features to drive the population to whatever pricing model works for them.
There's a tipping point where public perception changes. Everyone just lives with monitored phone calls because they chose to have it and the costs seem small compared to the benefit. (Free i-Phones! With 50 Cent and Halo for free!) Once it gets past that point, ad-free, suscriber-based service becomes expensive because the numbers aren't there to support those services. So they raise prices, and suddenly you can't "afford" to avoid the ads. That's if they decide to offer it at all.
I'd say that within 10 years, there will be data storage so plentiful, that someone can and will record everything that comes out of your bluetooth-miked mouth.
You want privacy? In the future, you'll have to pay a premium for it. Everyone else will have sold out long ago.
In America, television watches you. Just ask Tivo.