Also, Google isn't brokering the information they gather. From what I understand they're simply using it to target ads (which is what they actually sell), while keeping the data itself very close to the vest.

If you've got something on offer, and want to know who might buy, Google won't tell you who is interested. They'll just deliver your message to the right people, and if you get a suitable response, you'll know that their service was worth the price.

There's a world of difference between the mediated transactions they have with their customers, and the exchange that takes place when the government says "hand over the data itself."