Way too expensive, the clients are proprietary except for the Linux one, and the amount of sponsorships they do just make them look more suspicious than anything.

It's a corporation. It is inherently not private. Your government will always be able to get its data. NSA can be presumed to log its activity, whether or not the corporation itself does.

Nothing. It's rumors and hearsay. Probably the only negative is an alleged data breach, but that is not confirmed.