They are actually not using proof of burn. Counterparty is a decentralized exchange that sits on top of bitcoin. As such, I don't think it should be minable, no

They are actually not using proof of burn. Counterparty is a decentralized exchange that sits on top of bitcoin. As such, I don't think it should be minable, not with proof of work and not with proof of anything. Proof of burn was used during an initialization phase (let's call it distributed minting) which is over. Should really check it out more thoroughly, it looks like a pretty neat idea.