How come cargo ships don't have there own security or carry weapons to protect themselves?

Why not hire companies like blackwater to protect themselves or have a couple guns on board in case pirates attack?How come cargo ships don't have there own security or carry weapons to protect themselves?
bird flu?How come cargo ships don't have there own security or carry weapons to protect themselves?
Two reasons.





First, when you enter a seaport you are subject to the laws of the country where you are docked. Not every country will allow for armed security on ships, you really can be denied entry to the port-it's the law.





Second, it's bad for business. Those cargo ships don't own that cargo. It's like a giant taxi. Would you ride in a taxi that has a reputation for bloody shoot-outs? No, taxi drivers like to have a clean taxi and a cleaner reputation.





If your cargo ships keep getting into bloody shoot-outs, I'd stop shipping my cargo on your ship, you might dump my cargo in the ocean to save your own skin. That's good for you, but it cost me millions in lost cargo. I'll call another taxi.