Also known as a NoGood.
A group of people who roam Highways, usually in Vans or old cars. While roaming, they tend to drink, listen to loud music, plunder, and look for trouble at local truck stops.
They may not have a boat, or even sail the seven seas. But they will raid your truck, and your SUV.
The most famous band of Highway Pirates, would be The NoGood Scurvy Crew from Kingston Ontario. They leave their mark (NGSC) on over-passes and Truck Stop bathroom walls along the 401.
"Keep your eyes on the road, there be Highway Pirates in these parts."
"I'm a Highway Pirate, baby!"
"God Damn NoGood!"