IOW, the Christian equivalent of the Barbary pirates.
Except that the real Barbary pirates were less motivated by religion than by desire for riches. Most of them were Christian renegades.
It seems that the act of taking up housing in a military manner, and fortifying an outpost, and launching raids against an enemy shipping route is a bit more than a *little* different from piracy.
For one- this was not for profit, but the cheapest means of sustaining a campaign. (Hell, SunTzu even wrote it- the bert way to fund a war is with the enemies goods).
So no, these were nothing like the Barbary Pirates.