A California teenager pleaded guilty Wednesday in a case involving the swatting of a Florida mosque among other institutions and individuals, federal prosecutors said.

Alan Filion, believed to have operated under the handle “Torswats,” admitted to making more than 375 fake threats against schools, places of worship, and government buildings around the United States.

An 18-year-old from Lancaster has pleaded guilty to making hundreds of calls falsely threatening to conduct shootings or detonate bombs at public facilities.