Also the distinction between navies and pirates was a lot less clearly defined than it is now.

Both John Paul Jones and Sir Walter Raleigh were regarded as pirates by their adversaries and as naval heroes at home.

And those two would be considered among the least piratic! The English Crown granted licenses that gave commercial vessels the rights to any plunder from Spanish ships and settlements. It was effectively a loose mercenary affiliation. Deal: We empower you to commit legally sanctioned piracy. In return you make life difficult for our enemies and cut us in on the proceeds. Soldiers in war were never as restrained as period movies would have us believe, so imagine being boarded or invaded by a desperate privateer crew with not even the semblance of honor and soldierly gallantry to moderate their behavior.

Ahem. Back to Steve.

I think it's allowed in the circumstances:

http://www.folklore.org/StoryView.py?story=Pirate_Flag.txt