system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does the Mercenary business work? Is it a legal enterprise?

I know there are private military contractors like Blackwater. How does all that work?
gpt
The term mercenary is a bit general, referring to those willing to fight or even kill in exchange for money.

You can hire people to *guard* people/things legally.

You can not hire people to *attack* people/things legally.