From social media and banking to online purchases, we all use passwords. They can be hard to remember, and we have millions of them, but more worrisome are the massive data breaches of companies that we trust with our online credentials, when our usernames and passwords can become exposed. Now there is a simple way to find out if your security has been compromised. Troy Hunt, an Australian security researcher has designed a website that lets you check to see if your email addresses and usernames have been involved in some of the biggest data breaches involving companies like Myspace, LinkedIn, Adobe, Dropbox and hundreds more. Hunt's new tool, called Pwned Passwords, has a staggering 320 million leaked passwords stored in its database, and allows you to enter just your password to see if they have been leaked in any of these hacks. To find out if your username, email address or password is on the list go to Have I been pwned?