Why You Can’t Stop SPAM on Bitcoin | with Peter Todd

"You cannot prevent arbitrary data from being published in Bitcoin transactions. Even at the consensus level… It’s mathematically impossible.” Legendary Bitcoin contributor since 2009 and self-described "weirdo with a fine arts degree," Peter Todd joins me to unpack the endless wars over Bitcoin's "true purpose," his pioneering work putting "spam" on the blockchain, and why he believes attempts to filter transactions are just “silly.” In this episode, we get deep into the history of using Bitcoin for data storage - which goes back, at least, to the development of Namecoin in 2011. Relatedly, we cover the history and long-fought governance battles around OP_RETURN, relay policy and our community's evolving definitions of "arbitrary data." Suffice it to say, the Filter Wars of 2024/25 are not new… they are simply one battle in a decade+ war we unpack in detail in this context-rich episode of Bitcoin Rails. In more detail, this episode covers: - The development of Open Time Stamps + Bitcoin's use in validating election data and beyond. - OPRETURN battles of the early days… and how its use has evolved over the past decade. - Why Bitcoin Core "should not try to censor transactions" and the "performance art project" (Libre Relay) that shows why. - Bitcoin as a "replicated database" and why blockchains may legitimately be useful outside of sound money. - Why preventing arbitrary data on Bitcoin is "mathematically impossible" …and trying to stop it is only distracting us from "more important" efforts, like the Great Consensus Cleanup @darosior. This episode of Bitcoin Rails is powered by: - Best In Slot — the leading API for Ordinals and BRC-20 data aggregation and indexing. - Spark — a statechains implementation advancing Bitcoin-powered payments. - Citrea — the leading Bitcoin rollup technology and BitVM alliance contributor. Timestamps: 00:00 Intro 01:19 Bitcoin Early Days 03:44 OpenTimestamps Project 12:22 Governance and Bitcoin Protocol Debates 26:36 The Blockchain Use Case Argument 35:46 Transaction Version Numbers and Standardization 38:30 Preventing Exploits and DDoS Attacks 40:10 Relay Policies and Economic Decisions 42:00 The Taproot Annex and OP_RETURN 45:07 Libre Relay 01:01:18 Future of Bitcoin and Soft Fork Proposals