Good in theory, not so much in practise though, just too many opportunites for eff-ups.
It reminds me of geocaching, a mate was into this in a big, big way, but one of the geocaching forum members wronged him BIG (that started off as nothing but snow-balled into a big issue and he got banned from the forum), he inflicted revenge by going around finding geocaches and removing them, permanently.
If I get the idea of this challenge, some smart alec (other than me) could eff this up in a right, royal way.
Having said, give it a go, I'm happy to be proved wrong.