Is it though? Who knows how Google has crafted their language and legal loopholes to "technically" delete your data in one way while retaining it in another? And that doesn't even get into things like PRISM.
The PRISM vs Upstream slide makes it very clear that PRISM requests are done through the front door, because PRISM-to-vendor communication is 'laundered' through the FBI.
It wasn't an all-seeing eye of Sauron that had full access to their backends.