Generating blackmail is not illegal, using it to blackmail someone is. Generating libel is not illegal, publishing it publicly is not illegal either although you can be sued over it.
Generating worms and computer viruses is not illegal last I checked, but disseminating them is.
My point is that generating is not illegal but sending is. Your whole point hinges on legality, so the distinction between legal and illegal seems pretty key.
Its amazing how biased that source is and how much it buried the lede. They were arrested for participating in a riot where someone attempted to murder a police officer. That's not just someone criticizing ICE on social media. If it was, half the posters in any political thread on HN would already be arrested.