Humans are hacking a lot now, but the scope, scale and speed of AI-enabled hacking is orders of magnitude more potentially disruptive.
With AI you have
1. Superhuman reaction time
2. Infinite duplicatability, thousands of agents can work in tandem
3. Superhuman breadth of knowledge of code, exploits, information
Also AI models are improving at a rapid rate
> 2. Infinite duplicatability, thousands of agents can work in tandem
Worse: you have local models they can install on infected computers, so this could easily be "millions" and might just about push "billions" (though phones are a much harder target because power required is still huge even if they technically fit in RAM).
And most importantly:
4. No guilt when violating human standards of ethics.