When you were a kid, did you ever wrap your bike around a tree?
You know what we mean. You were out riding around and having fun with a bunch of your friends, and then did something meant to impress them that, in retrospect, turned out to not be very bright thing to have attempted, with the result of that unfortunate life lesson involving extensive road rash treatment for yourself and the need to untangle the frame of your hopelessly damaged bike from the tree trunk where it impacted.
Now, what if the frame of your next bike was designed to be wrapped around a tree, post or other object? And what if that was a key selling point for the bike? Would you be interested?
It could well be if you were concerned about the risk of having your new bike stolen. In fact, the fear of that risk motivated three Chilean design students to develop a bicycle frame with an integrated locking device - one where the bike would be rendered completely unrideable if it were ever cut. Via Core77, meet the "Yerka":
One thing we appreciate about the bike's design is that it eliminates the need to carry a bike lock while riding, which boosts its convenience factor. The trade off for that capability though is performance - the bike's frame will be heavier and less capable of absorbing impacts than a traditional frame design.
It also differentiates it from this competing concept, which basically makes the seat into the bicycle version of the "Club" steering wheel lock. 
But that also means that the "Yerka" shouldn't be ridden in a way where the frame might accidentally get wrapped around a tree on accident!