They were made in an online game run by Jagex, most likely RuneScape, which is what led to his arrest.
Frongillo allegedly said, "I'm going to shoot up my school tomorrow," and indicated a knowledge of firearms to other players in the game. He also made anti-Semitic comments and had indicated shooting at small wildlife in previous chat sessions. Jagex employees notified the police, and he is currently on bail pending his court date on April 19th. Frongillo's lawyers claim that the statements were made in jest and that the young man had no intention of carrying out any acts of violence.