Most of the users start AWS with one-year free tier account. There were many hacking incidents for such accounts which ended up in huge monthly bills. This happens because of many reasons, For example, you may commit your code to a public code repository with your AWS access and secret keys and a hacker would get access to account and launch high capacity instances. This would result in a huge monthly usage bill. We can avoid account being getting hacked just by applying few security policies and following best practices.