1) Brigandage 2) Pillage 3) Pillaging 4) Plundering 
Banditry is the life and practice of bandits. The New English Dictionary on Historical Principles (NED) defined `bandit` in 1885 as `one who is proscribed or outlawed; hence, a lawless desperate marauder, a brigand: usually applied to members of the organized gangs which infest the mountainous districts of Italy, Sicily, Spain, Greece, and Turk......
[n] - the practice of plundering in gangs
noun the practice of plundering in gangs