bitcoin

Supertestnet's gotcha: BIP16 also confiscated coins

Scoresby

The P2SH case is an interesting reminder that Bitcoin’s history is not perfectly aligned with the principles we like to articulate today. When people say UTXOs are sacred it is usually framed as an unbreakable moral and technical stance but the truth is that consensus rules have already invalidated some outputs and most node operators accept that without thinking twice.  

The fact that the frozen outputs in question were anyone can spend and that the total value was negligible does make the situation different in scope and impact compared to the idea of locking up funds secured with private keys. That distinction matters from a property rights perspective since the former had no clear owner while the latter would be cutting off someone from cryptographically provable control of their own funds.  

That said the broader point still stands. Absolute positions tend to fall apart when tested against real world historical edge cases. If you run modern Bitcoin Core you are already preventing the spend of certain outputs and this is part of living with a chain that has evolved through soft forks and changing validation rules. In principle you can remove that rule from your own node if you truly reject the idea of confiscation but in practice almost nobody does because the costs of consensus divergence are high