[Cryptography] Question about Bitcoin's security model

[David Kane-Parry]

On 22 Jul 2026, at 19:41, Jon Callas <jon at callas.org> wrote:
> On Jul 21, 2026, at 15:49, Roland Ionas Bialke <webmaster at pro-wrestling.biz> wrote:
>> 
>> - There is also the possibility to insert illegal media content into the transaction history - like "cheese pizza". In the past there was rumours about it, but no proof. When illegal media content would be in the transaction history, everyone who is loading it down would be in the posession of illegal media content.
> 
> This has already happened. I might be misremembering, but as I remember someone put a piece of CSAM into the bitcoin blockchain; NCMEC has removed it from their corpus, as I remember.

Indeed, this was published in "A Quantitative Analysis of the Impact of Arbitrary Blockchain Content on Bitcoin" at https://fc18.ifca.ai/preproceedings/6.pdf .

- d.