From the FCC website (Q & A) about spoofing:
What can you do if your number is being spoofed?
If you get calls from people saying your number is showing up on their caller ID, it's likely that your number has been spoofed. We suggest first that you do not answer any calls from unknown numbers, but if you do, explain that your telephone number is being spoofed and that you did not actually make any calls. You can also place a message on your voicemail letting callers know that your number is being spoofed. Usually, scammers switch numbers frequently. It is likely that within hours they will no longer be using your number.
So...the FCC will basically do nothing.
