a person in total disregard for the law / safety, at certain point. regardless of the outcome or risk.
like if u have a suspended license, your driving drunk, with drugs and/or a gun on u, speeding, blowing red lights / stop signs, and ur on probation. u could say that "your/hes/im/were in vigilante mode"
"chill ur on probation"
"fuck that shit nigga im in vigilante mode"