My inner paranoid finds this interesting from the perspective of Google entering yet another domain where they have high accuracy data on the present/future whereabouts and private concerns of a large number of people.. add it to the hundred other properties they maintain that appear to have no direct business value other than capturing masses of sensitive data that was previously nicely decentralized and private.

Can't book a flight (ITA), order a taxi (this), book a hotel or chat with a friend (Gmail), or pay for dinner (Wallet) without generating an activity log with a single company.

Even if (and perhaps even probably) Google weren't doing this intentionally, they've already demonstrated through failing to encrypt their inter-DC connections how they're becoming a massive single point of failure (remember Snowden showed us the NSA were tapping Google's internal network already). Whether the end result is an intelligence service tap, or some legislative measure affecting the company done in the open, I'll simply never be comfortable with one company concentrating so much personal data affecting so many people.