[redthrowaway]

Doesn't appear images are actually stored, just linked. So imgur or whoever would, presumably, remove it and miners would just have a broken link in their blockchain.

I can't think of plaintext that would be both illegal and small enough to store in the blockchain.

[viraptor]

Extortion and threats are both short and illegal in the US. Ideally, it would only be illegal to create them in the first place, not copy them because it happens to be a part of some dataset, but IANAL.

[redthrowaway]

I can see this being a pretty terrible tool for doxxing.

[viraptor]

"This contract contains all your private information, embarrassing life stories and more. Pay $100 per month or decryption key will be released." ?

[redthrowaway]

Blackmail is certainly a concern, but even garden variety harassment would be made far more harmful by the inability to have it removed.