“Would you stop running your full node if you found out that there was child porn encoded in the blockchain?”

The question, posed by ethereum developer Vlad Zamfir through a Twitter poll last week, has been discussed before, but it’s recently resurfaced after a widely-publicized report from RWTH Aachen University found one graphic image of child porn and 274 links to content depicting child abuse stored within the bitcoin blockchain.

The report goes on to contend that because downloading or transmitting child porn is a sex crime, participating in bitcoin as a miner or node operator could be illegal.

While the report didn’t explicitly compare this issue to the laws of any particular country, it’s particularly notable in the U.S., wherein Congress recently passed a controversial bill package dubbed SESTA-FOSTA that looks to hold internet service providers (ISPs) and other internet users liable for illicit content that they share, whether unknowingly or not.

Up until SESTA-FOSTA passed, section 230 of the Communications Decency Act protected ISPs and other internet users from this kind of transmission, saying that they would not be “treated as the publisher or speaker of any information provided by another information content provider.” Currently, it is unclear whether section 230 will be completely nullified by SESTA-FOSTA.

As such, the crypto community more broadly has been debating the merits of the RWTH Aachen University paper and what could possibly happen as governments work to clamp down on illicit activity throughout the world.

Zamfir’s poll, for instance, got 2,300 responses – only 15 percent said they’d stop running their bitcoin full node if child porn is encoded in the blockchain. And Princeton professor Arvind Narayanan tweeted that the mainstream media’s response to the report was “unsurprisingly superficial,” adding, “First, the law is not an algorithm. Intent is an important factor in determining legality.”

Still, this raises ethical questions about immutable ledgers that allow anyone to add unmoderated data to a shared, immutable record.

Speaking to this issue, Cardozo Law School professor Aaron Wright, who’s also the chair of the Ethereum Enterprise Alliance’s Legal Industry Working Group, told CoinDesk:

“It’s part of the tension between this hard to modify data structure, the blockchain, and the requirements in certain pockets of law. In the U.S., it can manifest itself in child pornography. In Europe, it can manifest itself in the right to be forgotten.”

Hidden pathways

But central to grasping the matter is understanding just what kind of illicit data is on the bitcoin blockchain. First and foremost, it’s helpful to understand that this content doesn’t appear in the form of JPEG images or video files that can suddenly pop up on a user’s computer.

The offensive content is instead housed in the blockchain in the form of links buried alongside all the other data sent with a transaction. As such, fishing this out and decoding it would take a great deal of effort.

Expanding on that process and addressing concerns of child porn, Washington D.C.-based non-profit Coin Center wrote in a blog post, “A copy of the blockchain does not literally have within it Bible verses and images but instead has random gibberish text strings that, if one knows where they are, one could put in the effort to decode them to their original form. Unfortunately, some sick individuals have also added encoded images of child abuse.”

Plus, every U.S. state’s handling of the disseminating of illicit material is different, but recalling Narayanan’s sentiment, most laws hold people accountable only if they “knowingly possess” or produce, sell, broadcast or access the content “with intent to view.”

According to Wright:

“If you need knowledge, you’d need to take affirmative steps and actions to disseminate this specific information.”

Since most bitcoin users have no idea which data contains these hidden pathways to illicit content, many believe RWTH Aachen University’s report was a bit misleading.

Not only that, but this issue doesn’t only exist for bitcoin; nearly all blockchains allow for data to be added to transactions, meaning anyone with the right technical skills could add the same illicit content to any open-source blockchain.

Dumping the data

Because cryptocurrencies have continued to garner more attention as of late, it seems many people in the community want to find solutions for the current illicit content that’s encoded in the bitcoin blockchain.

Cornell University professor Emin Gun Sirer took to Twitter to explain that “regular cryptocurrency software” lacks the decoder tool needed to reconstruct content from a specific encoding. But since it’s not impossible, he continued, network participants could remove the content by choosing not to store the content of some transactions, instead only storing “the hash and side effects.”

Along similar lines, bitcoin developer Matt Corallo said knowledgeable developers could also encrypt questionable data or find other ways to make it inaccessible.

“If having such information in the encrypted form is okay, then simply encrypting the data at rest would solve the issue. If it’s more than that, there are still workarounds,” Corallo said.

Yet, he continued, saying that more clarity is needed in defining what’s exactly illegal before the developers can address these things.

What is clear, though, is that if a node operator or miner is personally adding or aware of someone else adding child porn to the blockchain, they are legally required to alert the authorities.

And while that could be challenging given bitcoin’s pseudonymous nature, Wright said there are ways for law enforcement agencies to track people down.

“If you are recording information to a blockchain, you often have a record of who was uploading that information. So much like with issues related to tax evasion or terrorist financing, you can mine through a blockchain and try to deanonymize who the party was who uploaded it,” Wright said, adding:

“A blockchain would probably not be a great place to store indecent or obscene information.”

Hard drive image via Shutterstock