I looked into it further, and it looks like bitcoind actually does confiscate some pre-P2SH outputs. For the sake of "simplicity," it applies the p2sh rules to all transactions in all blocks (including pre-P2SH blocks) except ones occurring in one specific block that the devs made a single exception for. Thus, the other exceptional outputs are now unspendable. Source:
GitHub
bitcoin/src/validation.cpp at 13891a8a685d255cb13dd5018e3d5ccc18b07c34 ยท bitcoin/bitcoin
Bitcoin Core integration/staging tree. Contribute to bitcoin/bitcoin development by creating an account on GitHub.
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Interesting, was the P2SH upgrade confiscatory?
Bitcoin Stack Exchange
Did the P2SH BIP-0016 make some Bitcoin unspendable?
The P2SH feature currently in use was introduced to Bitcoin in 2012 with BIP-0016.
It was successfully activated on 2012-04-01 with block 17380...
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One of the things I like about bip143 is its detailed specification of the segwit sighash algorithm, screenshot attached. Why isn't there a bip that outlines the corresponding specification for pre-segwit (legacy) transactions? image
My latest invention is Lotto Miner, a webapp where you can attempt to mine a bitcoin block in your browser and put the block reward directly in a bitcoin address of your choice. You can also mine on regtest, where you are more likely to succeed. Try it here:
Lotto Miner
 Video demo: The difficulty setting is low at first, but you can increase it til it matches that of the real bitcoin network. Raising the difficulty will take increasingly more work and, probably, more time. The source code is:
GitHub
GitHub - supertestnet/lotto_miner: Playground for solo-mining bitcoin on regtest and mainnet
Playground for solo-mining bitcoin on regtest and mainnet - supertestnet/lotto_miner
 I made this to help folks learn how bitcoin's difficulty assessment algorithm works and gain an appreciation for how much work goes into mining bitcoin blocks. Also, I'm not aware of any open source tools for creating custom bitcoin block templates on regtest, and this is a starting point for such a tool. The codebase is pretty small and since it produces valid regtest blocks, devs should be able to customize it to suit their regtest needs. Try it out and have fun!
Lotto Miner
My latest essay is about bitvm. I outline how two bitvm firms plan to use a very expensive mitigation of the "data availability problem" in their sidechains, and I propose an improvement based on one of the lightning network's best cost-saving features.
Telegraph
A forthcoming problem with bitvm
Introduction In the past few months, several bitvm companies announced preparations for launching on mainnet, and I began to research their plans. ...