Fake caller-id is a difficult technical problem. The FTC is giving it a lot of attention, and it'll be a large part of the agenda at the upcoming meeting of the intergovenmental London Action Plan in Dublin in June.
The problem is that the SS7 signalling network was designed in an era when there were relatively few phone companies, and they were all well behaved. These days, anyone with a VoIP switch can inject CLID data and while most providers behave themselves, some don't, and the system provides no easy way to trace the bad data back to the source. Even worse, through the magic of the intertubes, even if the person calling you is in the US, the call may be routed through a sleazy provider in another country.
The regulators are putting pressure on the telcos to clean up, and to provide the tools to catch the bad guys, but it's a long slog. People who work for the FTC get the same junk calls as anyone else and are just as annoyed by them as the rest of us.
***** Moderator's Note *****
Ironically, SS7 was put into service to reduce Blue Box fraud, which was made possible because those whom designed the network couldn't conceive of a future where someone would break the rules for commercial gain. It just wasn't in their world-view.