I 2nd jetsfan92588's sentiments... IANAL, and while I am generally more paranoid than average when it comes to this stuff, I do think google would be making a big mistake if they were, in fact, recording conversations (as opposed to recording voicemail messages which are transcribed). Reason being those all-party consent laws in many states. Again, not talking about federal wiretapping, just private industry here.

Analog lines are really easy to tap with analog equipment, and I could be sitting outside your house or in your building's phone closet, or who knows where else.
VoIP type lines I'm sure have their own weaknesses as far as packet sniffing and reassembling, or even software intentionally recording calls. Both are insecure, have laws surrounding the issues, and could probably apply HIPAA standards for phone use to either if analog vs digital/voip isn't specified in the document.