Michael Arrington is not happy that Google Voice displays/exposes the caller’s Google Voice number when they are not calling from their Google Voice number:
I’ve had a nagging frustration in my otherwise perfect relationship with Google Voice. The service systematically replaces my friend’s phone numbers with their Google Voice numbers when they call, even when they aren’t calling from Google Voice. Not only has this led to a lot of confusing and time wasting “how did you get my Google Voice phone number?” conversations, it is a clear violation of Google’s own privacy policy.
Read more on Washington Post’s TechCrunch.