IT security is "hard" in the same way that the universe is "big". Just because the words "hard" and "big" are small words...doesn't mean that the concept being conveyed is in any way small.
One of my guilty pleasures is regularly grinning at the sheer cleverness and devious smarts that underlie many security attack vectors. Via John Naughton comes this absolute gem to do with encrypted hard disks. who would have thought that canned air can be a hackers tool?: New Research Result: Cold Boot Attacks on Disk Encryption