Vigilantism is nothing at all akin to out of control government employees.
The folks who comprise the vigilants should by all rights have a justice system they can avail themselves of, the mere act of vigilantism screams failure of the existing system of justice,(Just-Us").
As the current system grows and flexes it's muscle I fully expect to see more common folks seeking justice for wrongs perpetrated against them either by members of the "Just-Us" department or those whom they protect.
You don't have to agree or accept it, folks are fed up and many of them have faith in the justice system described in the constitution...
Much better in my opinion to shun the "Just-Us system and institute a fair and impartial justice system that actually dispenses justice...If such a system can be implemented vigilantism will be virtually non-existent..Except in the eyes of those who support the current dysfunctional system, they'll still call justice vigilantism..