Schools across the U.S. have been rocked by a spate of false threats of violence in recent weeks, forcing them to evacuate or temporarily close. Why it matters: Threats of bombs, shooters and other dangers disrupt learning and stir community-wide anxiety about school safety.

Threats against schools are increasing following a shooting at a high school in Barrow County, Ga. It is a recurring phenomenon that follows many tragic events.

Schools all over the nation have seen a spike in the number of threats received on social media. One school that's seen itself in this situation is Mountain View Middle School in Lamont.