A member of the broader alt-right movement, Cantwell earned attention during and immediately after his participation in the August 2017 Unite the Right rally in Charlottesville, Virginia.[17][18] Cantwell was featured prominently in a Vice News Tonight documentary about the rally and its participants, in which he is shown threatening to kill protesters, wielding rifles and a handgun, and joining fellow antisemitic conspiracy theorists in marching with tiki torches, chanting "Jews will not replace us!"[9][19][20]
Shortly after the rally, Cantwell published a video in which he wept while sharing that he had learned there was a warrant for his arrest. The video went viral, with some observers noting the discrepancy between the emotional video and the tough persona Cantwell had projected in the Vice documentary.[19] He has since been widely referred to and ridiculed as "The Crying Nazi".[24]
In July 2018, Cantwell was convicted after pleading guilty to two counts of misdemeanor assault and battery for pepper spraying two people at the rally.[21] On September 28, 2020, Cantwell was found guilty on one felony count of transmitting extortionate communications and one felony count of threatening to injure property or reputation.[25][26][5] Cantwell was sentenced to three years and five months in prison on February 24, 2021.[27][28] The charges stemmed from Telegram messages Cantwell sent to a member of a rival neo-Nazi group, in which he threatened to rape the man's wife in front of his children if he did not give Cantwell information about the identity of another member of the group.[29][30]
In 2021, Cantwell and others were found liable for civil conspiracy and racially motivated harassment or violence in Sines v. Kessler, a federal civil suit against organizers, promoters, and participants in the Unite the Right rally.[31]