Can we detect transaction censorship by mining pools on the Bitcoin network? I spoke at the MIT Bitcoin Expo 2022 about mining pool transaction selection, my miningpool-observer project, and observed extra, missing, and conflicting transactions between my block templates and the blocks mined by pools. I conclude that we can detect large scale transcation censorship by but haven’t seen any concrete evidence for censorship attempts yet. video (YouTube) slides (RevealJS) slides (PDF)