The first thing you may want to do before getting in the debt collection business, debt collection 101 let's call it, is learn the correct spelling of the word debt.
noted!
In regards to the legality of it, I think this is open to interpretation. Not paying a peer loan is still considered theft. Also, in the spirit of System D and bitcoin creating a government-free, independent database again seems like the right way and nothing more than a more elaborate OTC implementation.
Again, I'm open to discussion... This is just an idea and a proposal...