My normal playstyle is just to blow the heck out of the enemy, but I decided to have a go and set my military to capture anything possible.
Last night (very late) a pirate carrier (with no escorts! How stupid!) entered one of my systems. I have long-range scanners so I'd seen it coming of course and I sent a fleet of two light cruisers and four destroyers to intercept it, the biggest ships I can build at the moment. The carrier didn't seem to have any defensive weapons, or any main weapons in general though. I've learned from experience so I have plenty of point-defence weapons on my ships and they took care of the fighters before the fleet sent over the marines. The carrier was captured in just a few minutes and is now a nice prize for my empire and is doing picket-duty for that system (with escorts!) until I can get the tech to upgrade it to my own design.
Pirate AI seems to be a little, um, 'lacking' though. Who sends a carrier out with no escorts? Admittedly the system only had a small starbase before I sent the fleet in, but it's still a silly tactic.
Edit To Add: DWUR uses the Expanded/Bacon mod so there's a gravity well that stopped the carrier from escaping, otherwise I wouldn't have been able to capture it I suppose.