With the price of tokens I think mass surveillance with AI is not a realistic use case.

There already is a mass surveillance. Presumably most electronic communication is monitored. I guess LLMs can likely do a somewhat better job but probably not worth the cost for the marginal benefit over existing technologies?

Similarly for "Terminators" or other AI killing machines... Isn't it cheaper to use a human? We have autonomous weapons already, like cruise missiles... Other than the movies what does a reality with LLMs pulling triggers look like? Cars are also "killing machines" and we're letting computers drive them...

Unfortunately if these things do start making sense for whatever reason they're probably going to happen. Private companies in general have no way to prevent their technology from being used for "defense" applications. Once that genie is out of the bottle it's not going back in.