Not a security expert, but I believe security applies too. It is difficult to claim a system as 100% secure. So long as what is being secured is less worth than the effort to hack into, you are good.
The crucial thing people tend to miss: Attacks scale. They can be automated. Your blog may not be worth the trouble hacking it, but hacking thousands of private blogs and abusing them for spam and only having to work out the attack once is.