Playing devil's advocate: if I did in fact grab one of my kitchen knives to defend myself against a violent intruder into my kitchen, I wouldn't expect to be banned from buying kitchen knives.

I'm not sure this is still a useful analogy, though...

No it isn't. There are warnings, but once a knife is yours you are free to do whatever you want with it, including reselling it to someone else. The idea of terms of service of using something is not something that typically exists with physical objects that one can own. They can't take your knife away from you because you decided to use it for a medical purpose without purchasing a medical license for the knife.

These knife and lead analogies don't map well to the reality of AI. Note: just talking about the analogy itself not the point you are making.

Edit: hell I get downvoted and look where the knife analogy got us. A load of weird replies miles away from anything related to AI or DoD.