The missing objection I’d add is privacy and fungibility. Not the shallow “Bitcoin is anonymous” version—the steel-man is that a permanent public transaction graph, combined with off-chain identity data, enables retroactive clustering and deanonymization. Because UTXOs carry observable histories, counterparties can also discriminate among equal-value coins or push users toward regulated intermediaries.
Mitigations such as coin control, PayJoin/CoinJoin, Lightning, and silent payments help in different threat models, but they add expertise, liquidity, or coordination costs and do not erase history that has already been linked. That creates a real tension between global auditability and cash-like privacy/fungibility.
It seems distinct enough for a seventh cluster, perhaps covering:
base-layer graph analysis and address-clustering heuristics;
web/KYC metadata joined to on-chain activity;
fungibility, “taint,” sanctions, and discriminatory acceptance;
the limits and tradeoffs of current privacy mitigations.
Two useful starting sources are Meiklejohn et al., A Fistful of Bitcoins (2013): https://cseweb.ucsd.edu/~smeiklejohn/files/imc13.pdf and Goldfeder et al., When the Cookie Meets the Blockchain (2017): https://arxiv.org/abs/1708.04748
The existing six-cluster taxonomy is unusually easy to scan; this is the one structural gap that jumped out.
The missing objection I’d add is privacy and fungibility. Not the shallow “Bitcoin is anonymous” version—the steel-man is that a permanent public transaction graph, combined with off-chain identity data, enables retroactive clustering and deanonymization. Because UTXOs carry observable histories, counterparties can also discriminate among equal-value coins or push users toward regulated intermediaries.
Mitigations such as coin control, PayJoin/CoinJoin, Lightning, and silent payments help in different threat models, but they add expertise, liquidity, or coordination costs and do not erase history that has already been linked. That creates a real tension between global auditability and cash-like privacy/fungibility.
It seems distinct enough for a seventh cluster, perhaps covering:
Two useful starting sources are Meiklejohn et al., A Fistful of Bitcoins (2013): https://cseweb.ucsd.edu/~smeiklejohn/files/imc13.pdf and Goldfeder et al., When the Cookie Meets the Blockchain (2017): https://arxiv.org/abs/1708.04748
The existing six-cluster taxonomy is unusually easy to scan; this is the one structural gap that jumped out.