It doesn't matter how careful you are, if you have accessed the web in any way your information is there. It's like using a credit/debit card the information is there and once used you are on the gird. It's all about money and information is a valuable and marketable commodity.
Every time you fill out a survey, get a rewards loyalty card, credit/debit card, power up your smartphone someone is there monitoring you. Even your printer has stored information on it's HD. In this day and age of Drones, CCTV's, The Cloud, Bluetooth,,,etc, no one is invisible! Big brother is always watching.