WASHINGTON (Reuters) - The U.S. Federal Trade Commission and a big coalition of U.S. states sued Facebook Inc on Wednesday, saying that it broke antitrust law and should potentially be broken up. Facebook is the second big tech company to face a major legal antitrust challenge this fall. The first out of the gate was the Justice Department complaint against Alphabet’s Google, which was filed in October. Previous to that, it had been known for more than a year that Google, Facebook, Amazon.com Inc and Apple Inc faced an array of antitrust probes on both the federal and state levels. Following are other lawsuits and inquiries in the United States regarding Big Tech: Justice Department lawsuit against Google: The U.S. Justice Department sued Google in October, accusing the $1 trillion company of illegally using its market muscle to hobble rivals in the biggest challenge to the power and influence of Big Tech in decades. State attorneys general probe Google: A bipartisan group of U.S. states plans to file an antitrust lawsuit against Google as early as December while other attorneys general, led by Texas, are planning a lawsuit focused on Google’s online advertising business. Justice Department investigates Apple: This probe, revealed in June 2019, appears to focus on Apple’s app store. Some app developers have accused Apple of introducing new products very similar to pre-existing apps created by other developers and sold in the Apple Store, and then trying to banish the earlier apps from the store because they compete with Apple’s new product. Apple says it seeks to have only the highest-quality apps in the app store. Justice Department probing Facebook and Amazon: In July 2019, the Justice Department said it was expanding its Big Tech probes to include “search, social media, and some retail services online” - an apparent reference to Facebook and Amazon. Federal Trade Commission on Amazon: In its investigation of Amazon, the FTC is likely looking at the inherent conflict of interest of Amazon competing with small sellers on its marketplace platform, including allegations that it used information from sellers on its platform to decide what products it would introduce.