This Can't Be True...

I was reading through a website, and came across this website that had 25 facts about sex you didn't know.

There was some interesting things there, but it was the last one that shocked me, it was;

* When men of the Walibri tribe of central Australia greet each other, they shake penises instead of hands.

This can't be true can it, what a bunch of fools. Stupid way of greeting each other.