This is the right answer. There's a ton of easy low hanging fruit ways to do absolutely horrible evil things with high potential body counts. I could sit here and brainstorm dozens.

Occasionally we see people motivated to do some of those things, though. And when they're not also complete idiots, they can cause big problems.

What would someone like the Tsarnaev brothers be able to do with the power of an unrestricted LLM? Well-financed cartels? Organized terrorist groups?

Yes, there used to be an uproar about stuff like the anarchists cookbook... and people did attempt some of the things it outlined. The saving grace is that many of the things in that book were just wrong anyway. They likely served as unhelpful misdirection as much or more than they were dangerous. Unfortunately, LLMs are a lot more accurate and helpful.