
Child abuse imagery found within Bitcoin's blockchain - asymmetric
https://www.theguardian.com/technology/2018/mar/20/child-abuse-imagery-bitcoin-blockchain-illegal-content
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rlpb
A miner who knows where in the chain these files are could zero out the bytes,
retaining just the hash of that area. Normal operation on the blockchain could
continue, except that the miner wouldn't be able to validate any new
transaction trying to spend the output that contains the illegal content. This
doesn't feel like a loss anyone is going to worry about. The only affected
parties would be the parties who put the data there, and presumably they
aren't going to reveal themselves.

In other words, Bitcoin operation can continue with pretty much a non-
controversial software change that allows miners to choose to ignore
particular outputs.

If a miner genuinely doesn't know where in the chain these files are, then I'm
not sure it can be claimed that the miner is in "possession" of it and the
legal principle of mens rea will mean that the miner won't be criminally
culpable in most jurisdictions.

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yetihehe
And no one had seen it coming? It's way better than bittorrent trackers, it
requires many many people to agree that something needs to be removed, but
adding any data to publicly held records is very cheap, so those that uploaded
pictures can do it again.

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odinho
How are they storing this? I understand the links, there is enough bits to do
that, but an image stored on-chain? How?

Over several transactions and you need to put it together, or will there be
enough space to store an image in a OP_RETURN script?

83 bytes doesn't sound like it's enough to store any abuse image.

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drchaos
Here's an article which describes how to store data in the blockchain, along
with some interesting (legal/SFW) examples:

[http://www.righto.com/2014/02/ascii-bernanke-wikileaks-
photo...](http://www.righto.com/2014/02/ascii-bernanke-wikileaks-
photographs.html)

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__blockcipher__
Haha, we can all see where this is going

“Only miners need the whole blockchain, and the blockchain contains illegal
data, therefore mining is equivalent to possession and distribution of child
porn...”

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ebcode
This is bad. Like, really bad. That "feature" of bitcoin has added more
complications to the network than it is worth, IMO. Either the law's gotta
change, or miners are going to start being prosecuted.

... or, the bitcoin developers will just have to add a way of removing that
data when a new block is mined, which I guess is what will eventually happen.
What a mess.

~~~
mschuster91
> That "feature" of bitcoin has added more complications to the network than
> it is worth, IMO

As long as there is _any_ option of storing _anything_ user-derived in the
blockchain, this problem will exist. And it is conceivable that the
transaction amount can be used to encode binary data... and this doesn't just
impact Bitcoin, but also normal banks. Assuming a bank with two accounts and
no transfer fees, I could transfer money between the accounts and encode my
data e.g. in the "cent" division, with every transaction encoding a single
byte. So technically the bank is in possession of child porn (or, to choose
something of lesser importance, the tiny libdvdcss code), but is
simultaneously not allowed to erase it due to financial transparency laws...

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solarkraft
however if you don't tell them how you encoded it, nobody would ever know. the
same way it would be possible to find something that could be considered
illegal by searching the right way in any large enough [random] data. so
where's the barrier?

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JohnTHaller
This would appear to mean that the 12,500-ish people running a full Bitcoin
node have child pornography on their machines. As do those with full nodes
that haven't been active in the last 24 hours.

~~~
commandlinefan
... that they can't easily remove.

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JohnTHaller
You can easily remove it by ditching your full Bitcoin node. Of course, you
can't really do that if you're doing some sort of business that relies on it.

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bandrami
Apparently there's leaked classified material in there too.

Well, that's a fiasco...

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staticelf
Price fall in 3..2..

