Firefox has a built in privacy deal called Privacy badger, blocks the trackers.
When I installed Firefox, all I could get was a black background. I couldn't change the color configuration on it. So I said screw it and went back to google. If you're on the internet, you're not private. Period. End of story.
I watched a show/video one day where a man turned off his brand new phone and went to certain stores around his community. Got back to his house, plugged it into his laptop. And found that even with his phone off, all the supposed tracking disabled, it still tracked him. And as soon as he went online with his phone, the info was then sent out to god knows where.