Maquis
From FEInfobase
The Maquis were a group of Federation colonists who opposed a peace treaty between the Federation and Cardassian Union in early the 2370s. They declared war against the Cardassians after a number of Federation colonies under the new treaty fell under Cardassian rule.
Professor Anthony Starling at one point was rumoured to be linked in to helping the Maquis.
Shortly after the Dominion War, almost all the Maquis were eradicated by the Dominion. Those who survived were given full pardons by the Federation and allowed to return to Federation space. Many Starfleet officers sympathised with their cause as it turned out they were right about the Cardassians' hostile intentions against Federation space (DS1: "The Vulcan Connection")