I came across a list of possible questions for a security panel and thought it may be interesting to apply some of them to MySQL and see what happens .
* What is the biggest challenge in data security?
I would suggest it is always the same problem with security - human error. It seems that no matter how well you protect the data, people will be the weakest link in the chain. This could come from social engineering, or to the point where the admin does silly things like deleting/dropping data from the wrong area.
How can we address this problem with MySQL? There are some configuration options that let you force safer interaction like safe-updates etc, but it will never be enough. Backups are probably the best answer.