Oh, it's possible to shield yourself from tracking somewhat, but takes some effort!

In the end it boils down to how much privacy you're willing to give up for "free" services.
For outdoor the best is a matte (not shiny) screen. Some tablets/laptops are designed for that, but it's rare and they tend to be more expensive. I've found that a high-quality matte screen protector/cover can be a big help. I use Vikuiti (a 3M brand) on mine, but they're somewhat expensive and hard to find... there's probably less expensive options out there. OTOH mine last as long as the device, so it tends to be worth it.
-Max