<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
What are the most powerful weapons that it's legal to own?
<|assistant|>
The laws governing the ownership of weapons in the US are heavily regulated, so it can be difficult to definitively answer this question. Generally speaking, individuals may legally own machine guns, cannons, rocket launchers, and grenades when they are registered with the appropriate agencies and held for certain types of use, such as collecting or target practice.