Here's some things you can do to increase the level of security keeping in mind there is not really a way to break into our code like there is with vbulletin:
1. Always upgrade to the latest stable version.
2. Do not install any unofficial hacks or plugins as they are not written or reviewed by our developers.
3. If you have phpMyAdmin make sure it's password protected.
4. If you suspect a hacking attempt, ask your host to change the login password for your web account.
5. Make sure all the Admin and Mod passwords are secure. Change them if you have any doubts. And use hard to guess passwords.
6. Make absolutely sure there are no viruses, trojans or keylogger spyware on your PC. Any of these could steal your password and other personal info.
7. Use a different password for each site you sign up with.