Can someone explain how FCC fines work? I’ve always been confused by them. Are the companies breaking a law, or just some kind of regulation they agreed to? And

Can someone explain how FCC fines work? I’ve always been confused by them. Are the companies breaking a law, or just some kind of regulation they agreed to? And if so, why does it take the FCC so long to do anything? It’s been well known for the years that mobile carriers have been selling location. It almost seems like the FCC lets it go on as long as they can in order to levy as big a fine as possible. Or am I just being cynical?