What the original author failed to mention (or likely never bothered to find out) was it's not simply 3 friends, but instead 3 friends from distinct social circles, possibly with a minimum mutual friend requirement or more.
When you choose the you're friend you want to verify, it dramatically limits the choice pool for the next two, meaning you can't pick 3 mutual friends, you need to pick yourself, their friend from back in college you don't know, and their sister. Harder to do than get any three friends to play a prank.
I certainly hope they stay my friends, and don't die before I need them.
Well, except by not having facebook (which luckily I don't have).