A single person acting in isolation (no friends, no colleagues, no customers) has very little agency. While theoretically a single person could release smallpox back into civilization, we have collectively selected it out very effectively.

The question is only relevant if AI is a significant force amplifier. If it is not, it is an unthreatening tool, whose usage should be largely unrestricted, this is the case now.

If that ever changes then there is the question what to do with it and at a certain level of power an individual decision would have impact, if sufficiently amplified.