bbchallenge.org/story#what-is-known-about-bb lists some (all?) cool examples,
wiki.bbchallenge.org/wiki/Cryptids contains a larger list. In June 2024 it was discovered that BB(6) is hard.
These can be viewed at bitcoinstrings.com/blk00052.txt and are mostly commented on the "Wikileaks cablegate data" section of Hidden surprises in the Bitcoin blockchain by Ken Shirriff (2014).
Soon after block 229991 uploaded the Satoshi uploader, several interesting files were added to the blockchain using the uploader, and notably some containing content that might be illegal in certain countries, as a test to see if this type of content would make the Bitcoin blockchain illegal or not:
So basically, this was the first obviously illegal block attempt.
None of this content is particularly eye-popping for Ciro Santilli's slightly crazy freedom of speech standards, and as of 2021, the Bitcoin blockchain likely hasn't become illegal anywhere yet due to freedom of speech concerns.
Furthermore, it is likely much easier to find much worse illegal content by browsing any uncensored Onion service search engine for 2 minutes.
Ciro Santilli estimates that perhaps the uploader didn't upload child pornography, which is basically the apex of illegality of this era, because they were afraid that their identities would one day be found.
Bibliography:
vCPU Updated 2025-07-16
apport-cli Updated 2025-07-16
Cat qubit Updated 2025-07-16
Bitcoin daemon Updated 2025-07-16
Runs just a headless Bitcoin server.
You can then interact with it via the Bitcoin CLI client.
On Bitcoin Core snap 26.0, the executable is called bitcoin-core.daemon rather than bitcoind
This is our primary data source, the first article that pointed out a few specific CIA websites which then served as the basis for all of our research.
We take the truth of this article as an axiom. And then all we claim is that all other websites found were made by the same people due to strong shared design principles of the such websites.

There are unlisted articles, also show them or only show them.