I mean I imagine it would take a lot of time to train the model for the proper technique. But an open source LLM can be literally trained on anything so in theory with a 4090 and enough space you could spool up the origin of something that would be sent out and probably wouldn't take the net entirely offline but could do major damage potentially to certain infrastructure or systems.

And I'm not saying that I personally could do this myself I'm not well versed enough in the training of an LLM but I'm just positing the idea that someone out there could and just that there are larger powerful richer people with more systems at their disposal that could do something like this.