lawfare
n. The use of legal means to fight a battle that would otherwise be waged by political or military means; legal action viewed as a form of war.
Etymology
Examples
2005
Lawfare, the second theoretical strand, represents one of the most interesting recent developments in military theory. More than 100 years ago, Prussian strategist Carl von Clausewitz wrote that war was a continuation of politics by other means; a way to impose a nation's political will by force of arms. Lawfare is best understood by turning Clausewitz on his head (sorry Carl)—it is a continuation of warfare by political or legal means. According to the Council on Foreign Relations, lawfare is the strategy of using or misusing law as a substitute for traditional military means to achieve military objectives. Partisans fire motions and discovery requests instead of artillery rounds.
—Phillip Carter, “Legal Combat,” Slate Magazine, April 04, 2005
2000
Fueled by the success of the class-action war on Big Tobacco, class-action "lawfare," if you will, is also now being waged against—among others—gun manufacturers, makers of lead paint, Microsoft, the health maintenance organization industry, makers of genetically altered seed, the vitamin industry and the airlines.
—“Litigation bug bites into democracy,” Chicago Tribune, January 10, 2000
1984 (earliest)
John Turmel, an Ottawa political fixture who has run in 16 elections, has also found time to appear in court about 100 times. "I'm sure I hold all records," he said. "I've also had seven motions in the Supreme Court of Canada.

"I call this guerrilla lawfare," Mr. Turmel says. "Who says that some peon can't pick up a rifle. You can't call him a soldier, but he can still shoot."
—Kirk Makin, “In the matter of self-defence,” The Globe and Mail, July 02, 1984