Security or cosmetology?

Ultimately, thinking things through is what matters most in security. Faling to do so inevitably results in cosmetic, rather than substantive, security. It is human nature to want to protect against yesterday's threat and be ready to refight last year's war, but doing so is obviously ineffective as a potential attacker will simply identify and exploit a different vulnerability. For example, Many of us take pride in the measures we employ to protect information on our personal computers, but few bother to encrypt the data in our PDAs. And the data we often keep on them: closely guarded passwords, bank account PIN numbers, combinations to safes, credit-card numbers, and so on, are often far more sensitive than what is in our PCs.