Security Now showed a easy way for a hacker or even plain websites to find out all sorts of information about you using the Form Fill function built into Chrome.
Websites can put up a Form Page, but put the fields off the screen. If you have Form Fill enabled, Chrome and other browser will automatically give the page all sorts of information about you and you will never know.
An easy fix for this is to go into Settings – Search for Form and then make sure the box is unchecked under Passwords and forms.
As long as you are there, you should probably also uncheck the “Offer to save your web passwords.
Also click on the Manage links and remove any information they have have stored in the past.