Written to the chain on 08 Apr 2013, block 230,229.
Index pages from the Hidden Wiki — a directory of Tor onion services — written into the chain in 2013 across two transactions. Placing a link directory somewhere no authority can delete it is a deliberate act, and one of the earliest arguments about whether Bitcoin's permanence is a feature or a liability. The contents are not reproduced here.
Bare multisig outputs list several public keys and say how many signatures are needed to spend them. Uploaders discovered that the public-key slots could carry arbitrary bytes. A transaction can include many such multisig outputs, each carrying one or more fake key-sized chunks.
More about P2FMSEvery byte shown here was read from these transactions. Open one in a block explorer to check it yourself.
