Threats of violence have sparked chaos at dozens of schools in Chicago and its surrounding suburbs since the beginning of the school year, leading to lockdowns, security screenings and days of remote learning.

As schools face a widespread surge in violent threats, districts have rushed to respond through parent meetings, local press appearances, and videos of students urging their peers to be careful what they post online.

Schools in at least 35 cities or counties across Virginia have been targeted in social media or direct threats since the beginning of the school year,