Doesn't mean that won't change in the future though. But log retention is only a matter of days, so they can't retrospectively change what they do to invade your privacy.
I hope Google doesn’t do this, but I would not be entirely surprised if they did.
Well, obviously I can't say for sure they don't have any. I didn't look it up, and if I had I wouldn't be able to tell you. But since I didn't, I can tell you that the concept seems completely infeasible. There's too much traffic, and nowhere to put them.
Besides that, not everything is legal to log. The frontends don't know what they're seeing, though; they're generic reverse proxies. So...
If there’s one company in the world for whom bandwidth and storage are not an issue, it’s Google.
But as it stands I don't want to trust Google, Facebook etc. more than absolutely necessary. They have lost every right to that a long time ago and are incentivized by their business model to not change anything.