The do not call list... does it work?

I was discussing the 'do not call list' with some folks and they were quite surprised and not too impressed to hear that the exceptions to the list (in other words, those that can call you even though you're on the list) include any company you currently do business with (your bank, cable company, cell provider, etc.). The problem is based on the often indecipherable terms you agree to regarding information sharing with 3rd parties when you have a business relationship with anyone. Those 3rd parties often use that information to call you and are likely protected by fitting themselves under the umbrella of being in league with the original party. I admit that my unsolicited calls have somewhat been reduced, but not as much as I would like.

In other words, the list is pretty useless.

So I have an idea. Whenever anyone calls you that you are not knowingly doing business with, you should be allowed by law to demand who they are aligned with that you are doing business with. That way, if you find yourself being harassed by 3rd party callers from - let's say - your bank, you can politely inform them that you will be terminating your business arrangement.