Excerpts from very detailed article:
Look, cybercrime is a real thing, from pig butchering to ransomware, and there's real, global harms that can be attributed to it. Cybercrime is transnational, making it hard for cops in any one jurisdiction to handle it. So there's a reason to think about formal international standards for fighting cybercrime.
But that's not what's in the Cybercrime Treaty.
In authoritarian states like China and Russia (whose delegations are the driving force behind this treaty), "cybercrime" has come to mean "anything the government disfavors, if you do it with a computer." "Cybercrime" can mean online criticism of the government, or professions of religious belief, or material supporting LGBTQ rights.
This is the granddaddy of tech free speech fights.
