Yesterdays pirate encounter: reasonable demand by a pirate Destroyer for 1 million credits (carried a Kamome load of oxygen.)
Conclusion: Cruiser piracy not so effective. I could dodge and kite him long enough for bomber support to arrive and mop it up.
I can however imagine that a larger less mobile transport would be in trouble, but what really svaved me was the thruster speed difference. Once you put a little bit of distance between you and him, it's a safe run home.
Note: piracy attempted at a gate and the destroyer was alone.