Threatening to shoot someone is not considered a violation of Facebook TOS: "Our update Thank you for taking the time to report something that you feel may violate our Community Standards. Reports like yours are an important part of making Facebook a safe and welcoming environment. We reviewed the comment you reported for having a credible threat of violence and found it doesn't violate our Community Standards. Please let us know if you see anything else that concerns you. We want to keep Facebook safe and welcoming for everyone."