Yet, hopefully we can agree that sql injections are illegal.
If we're slicing on technicalities, there's a lot of ways to decide. "PROSECUTE THEM!" seems like an extremely hostile one when the website and readme and release notes said "don't do this" already. The agent ignored those things? Is that the author's fault?
Say I lay a log on a road which you can clearly see and avoid but choose to drive over and crash your car, that’s prompt injection.
One is way worse than the other.
You are authorized to do what the user agreed to, no more. Further the agreement must be reasonable. Exploiting the victims system to intentionally cause harm isn't reasonable.
F-secure once included a clause to use their wifi that you "assign their first born child to us for the duration of eternity." It was funny, but not legally enforceable and would have offered them no legal shelter if they'd gone out on a kidnapping spree that night.
When it comes to responsibility, usually we consider a person intentionally doing something that they reasonably believe will have some consequence as responsible for that consequence. Especially when the primary reason they took the action was to generate the consequence. Excuces of the form "Technically i didn't do it, i just knowingly did something for the explicit purpose of triggering some downstream consequence" generally do not fly.