专家警告说, 网上极端主义加剧了美国单独行为者袭击的威胁。 Online extremism fuels rising threat of lone-actor attacks in the U.S., experts warn.

线上极端主义和政治两极分化正在增加美国发生暴力攻击的风险,现在孤立的行动者被视为主要威胁。 Online extremism and political polarization are raising the risk of violent attacks in the U.S., with lone actors now seen as the main threat. 受到各种意识形态,包括极右和极左思想的启发的激进主义,由于威胁的分散性质,对执法构成挑战。 Radicals inspired by a variety of ideologies, including far-right and far-left, pose challenges for law enforcement due to the fragmented nature of threats. 专家指出,虽然激进化是广为人知的,但向暴力的移动更难预测,袭击者没有典型的特征。 Experts note that while radicalization is well understood, the move to violence is harder to predict, and there's no typical profile for attackers.