Re: A weaker system
The telcos kept this information already. Worst case someone hacks into them and knows who you called/texted. That's not a problem in general, only if they're able to target you and do that specifically (think mob hits, stalking battered wives, etc.) How do you think they know what to bill you? Maybe not today with unlimited everything, but a decade ago when you were charged per minute on each call and per text, and AT&T would send you a 10 page paper bill detailing every single call and text message...
The telcos aren't keeping what you're saying, just the info on what numbers you called. Even the NSA's new billion dollar datacenter couldn't come within three orders of magnitude of storing months worth of actual texts and calls, so they need this big haystack to determine which quarter million numbers to bug and intercept all calls/texts to/from to form the smaller haystack.
If you think that's too broad a net and they'll probably miss the next 9/11 because they'll have too many suspects and too much data, I'd heartily agree with you. Bugging everyone with two degrees of contact separation from the thousands of tier one terrorist suspects is a fool's errand.