The efficacy of nonviolence was also challenged by some anti-capitalist protesters advocating a "diversity of tactics" during street demonstrations across Europe and the US following the anti-World Trade Organization protests in Seattle, Washington in 1999.
非暴力的效果也受到了一些反资本主义抗议者的挑战，他们主张“战术多样性（英语：diversity of tactics）”，并于1999年在华盛顿州西雅圖发起反世贸组织的抗议活动后，又在全欧洲和美国举行示威游行。