Web browsers come with features to improve user experience. One of the most popular ones is auto-fill passwords. These are designed for users to store and automatically use their account credentials to access websites and other applications. While auto-fill passwords are convenient, they come with security risks.

Advertisements and “helpful” suggestions based on your internet browsing habits can be troubling. But what’s even more alarming is that hackers have found another way of tracking you via seemingly harmless autocomplete passwords. Here’s what you need to know.

Passwords are a double-edged sword. If you make them too simple, they’ll be easy to guess; if you make them too complex, they’ll be impossible to remember. One solution is to create an uncrackable password and save it to your browser. Unfortunately, recent research suggests that tactic could drastically reduce your privacy.