The Sky Raiders are a mercenary gang that operate in the now-defunct City of Heroes MMO.
They pride themselves in using advanced technology, including stolen Rikti technology, that give them the means to fly.
The Sky Raiders were originally a secret government defense group codenamed "Vigilance". Designed to bring down super-powered threats, including possibly hero groups like the Freedom Phalanx, "Vigilance" was given cutting-edge armament and equipment, which also included technology "borrowed" from said hero groups.
"Vigilance" operated in secret, primarily for the United States, but they also worked for mega-corporations to help bolster their equally secret financing.
When the Rikti first invaded in 2002, the team was quickly deployed. But even their so-called "cutting-edge" technology was no match for the advanced Rikti technology. "Vigilance" was devastated quickly.
After the Invasion ended, what was left of the organization was regrouped and tried to mop up the Rikti stragglers that hid in Paragon City. But then, suddenly, the whole unit disappeared.
Soon after, a terrorist group using the "Vigilance" equipment and calling themselves the "Sky Raiders" tried to hold Paragon City hostage, claiming superiority over the airways. Their "siege of the sky" was short-lived as a large group of superheroes rallied together and took down the Raiders. Most of the forces, all former "Vigilance" members, were arrested, and their equipment was confiscated and locked away.
Most, but not all of the members were taken down. However, their leader, Colonel Duray, managed to escape thanks to a new mysterious financier. With his newfound money, he was able to quickly rebuild his new group and make their services available for the right price.
(See their Paragon Wiki entry for more information.)