So much has been written lately about security and privacy, particularly because of the Apple vs. FBI feud. It scares me that so many people with the potential to influence the final outcome don't seem to understand the technical issues, nor the long term implications. The same technology that protects my family and me also protects the US President and any Americans overseas in scary countries without many civil liberty protections.

Blake Ross' excellent wise-guy summary gives some great real world examples of security that everyone can understand, but also does a great job of giving a cliff notes overview of why building secure software is so difficult. Also, I had somehow never known the details of how they secure airplanes now:

"For as much money and time as we’ve wasted on printer-powered air security, only one innovation has prevented another 9/11: Locked, reinforced cockpit doors. These doors can withstand gunfire and even small grenades.

But sometimes, 6 hours into a Cancun flight, 3 helpings into Delta’s Cargo-Class Seafood, a pilot needs to deposit a few small grenades of his own. So there’s a handshake protocol:

When the pooping pilot wants to reenter the cockpit, he calls the flying pilot on the intercom to buzz him in.
If there’s no answer, the outside pilot enters an emergency keycode. If the flying pilot doesn’t deny the request within 30 seconds, the door unlocks.
The flying pilot can flip a switch to disable the emergency keypad for 5 to 20 minutes (repeatedly)."