The Home Office said the content of calls and texts would not be read and insisted the move was vital to tackle serious crime and terrorism.
The only info being kept (that we know of) is metadata about the location of the phone, who called, etc.
Even with the expectation of complete privacy (in the bedroom, for example) you can't expect that your location will be kept private as well.
We know you're in your house, we just don't know what kind of farm animals you are molesting
I'm all about privacy, but I just don't see this as a privacy issue, since the information has been available for as long as the ability to keep records has existed.
Now, if you want to shine up that tinfoil hat and get all scared about big brother:
AT&T is still directly monitoring calls made in the USofA for the gov'mint.