Who will run the CoinJoin coordinators?

Joinmarket, while innovative in its approach to enhancing the privacy and anonymity of cryptocurrency transactions, falls short of completely addressing the centralized communication coordinator issue. This limitation is not unique to Joinmarket; similar challenges are observed with CoinShuffle and its advanced iteration, CoinShuffle++. Despite improvements, both protocols still depend on a form of coordination, termed a "bulletin board" for CoinShuffle(++), to facilitate communication among participants. This necessity for a coordinator or bulletin board to receive and broadcast messages introduces complexity, particularly in assigning participants to sessions, which remains a significant hurdle in the practical implementation of CoinJoin-based solutions. These issues underline the persistent challenge of coordinating decentralized transactions without sacrificing privacy or efficiency.