Yes, there is a whole range of issues here. I've spoken in the past on this.
There is a real burden on individuals, ordinary people, to determine what level of protection their communication has. When we send a postcard, we don't expect much privacy. If we send a sealed letter, we expect privacy. If we have a telephone conversation or if we send out e-mail, what is the privacy expectation for e-mail? It's not a lot either, because e-mail bounces around in places before it reaches its destination. At every one of those places it could be determined. That's why, for people doing important business, you should consider encryption; otherwise you won't get any privacy protection.
Then you go on to these other technologies, the variation of a telephone to cell and so on. There are some real concerns about how the ordinary person determines what's protected and what isn't. You then have to lower your expectation or raise your expectation, and I think there is a real problem.
I don't see why, in principle, cellphones should be excused. Why are you making a land line...which doesn't necessarily mean a land line either, because you're sending it on a fixed line for part of the time but for a part of the time it's going over communication towers, so nothing is well defined that way. I think the simplest notion is that general forms of communication have to be protected, but there are going to be distinctions and problems in certain kinds.