Justin Trudeau was pelted with gravel while at a campaign stop in London, Ont. The attack came on the heels of some fiery protests throughout the Canadian election campaign where Trudeau had been assailed by angry anti-vax protesters.To at least one expert, the violence on display towards Trudeau is relatively unsurprising given some of the rhetoric online and at his protests.“I think there’s increasing concern that this violence is becoming organized, that there are far-right movements that are intersecting with the anti-vax movements,” said Stephanie Carvin, an assistant professor and national security expert at Ottawa’s Carleton University.