How are local, state, federal, and international law enforcement agencies monitoring social media accounts for those who have been identified to be a threat to the global community?

How are local, state, federal, and international law enforcement agencies monitoring social media accounts for those who have been identified to be a threat to the global community? What detection and monitoring strategies are being utilized by law enforcement? Are they effective? Why, or why not? Discuss a real-world example. Lastly, discuss at least one recommended strategy that could be adopted by the law enforcement sector to counter social media threats.