WASHINGTON - The man who runs Blackwater USA is defending his private security firm against charges that his staff has acted like a bunch of cowboys in Iraq and Afghanistan.

Erik Prince told a House of Representatives committee he believes his employees have acted appropriately.

But the panel's chairman, Democratic representative Henry Waxman, wonders whether outsourcing security operations is the right way to go.

He cast Blackwater as a rogue mercenary force that may be overcharging the government.

The FBI is investigating Blackwater personnel for their role in a shooting last month that left 11 Iraqis dead.