At the risk of sounding like a broken record we can't emphasise the importance of keeping your website secure. You might think its overkill and a risk you are willing to take but we can guarantee you after being hacked once you will change your mind very quickly.
Hackers can steal user information, passwords, install malicious software, and can even distribute malware to your users. And all that without taking into consideraton the costs involved in getting your website and information back online if taken down.