Since privacy is a key differentiator for them (huge financial incentives to actually deliver and not just pay lip service), and there are significant penalties waiting for them if they are lying about protecting privacy (as well as plenty of people who would love to call them out on it), Apple is probably the most trustworthy of any organization if you care about privacy. Also you can keep your data local with Apple hardware - it's encrypted and only available to your hardware - obviously a lot of the functionality they profiled today doesn't work if you take that stance, but it is an option.