>What if I specifically tell it to not do anything nefarious or illegal?

Typically the avenue for lawsuits would be under "negligence" or "recklessness", so it'd be up to a judge/jury to decide what a reasonable level of care is. "specifically tell it to not do anything nefarious or illegal" isn't an airtight defense though. If you told your tesla FSD car to drive itself and not break any laws, but then it crashed into something, you'd still be liable.

>(because it’s marketed that way) then how could I be held liable?

then it becomes a product liability lawsuit where they sue you, and you sue the AI company.