A Virtual Private Network like VPN Unlimited is the solution to your privacy woes. Using VPN Unlimited will hide all of your online activity from unauthorized spying, be it from prying government eyes or data-hungry internet service providers looking to sell your profile back to advertising companies.
Every person who carries a WiFi enabled device with them can be tracked. The people they're with can be tracked. Even if you have the WiFi on your device turned off, the device will occasionally turn it back on to "look around".