Trying to be optimistic, but...
Given the corporate track record, it's hard to believe the personal data won't be abused...
Having said that, I confess that I'm pretty sure that I qualify as a heavy user of these devices. In fact, right now I'm in the market for a new sleep meter. Does anyone know of some good online database comparing the various features? When I was shopping for my first sleep meter about a year ago, there were only 3 or 5 options in the stores, but on my latest visit, it seemed like at least 30 options. Then there's the exercise trackers, the BP meters, and fancy scales, many of which have options to feed smartphone apps... Just feels overwhelming.
Not exactly a comprehensive solution, but let me mention that EdX is offering a class on this topic, starting next month. I think Rice is the primary sponsor, though Baylor Medical School is involved, too. Even if I can't find such a database, maybe the class will help me understand the most important evaluation criteria?
Now we return you to your regularly scheduled worrying about corporate abuse of your personal information...