CAs are the worst violators for disabling Caller ID or spoofing it.
A bill in the Senate might make that illegal.
Up to a $1 million fine for a single act, but there appears to be no individual right of suit against the violator.
Still, if it passes, and once it's law, if a CA calls and uses a spoofed phone number, take a photo and report 'em to the authorities.
"Well, Mister Jones, you've called me three times in the last week, and each time you've used a different phone number that doesn't appear to be valid. I tried to call the numbers displayed on my Caller ID unit and they weren't valid. It would seem you're illegally spoofing your phone number. I don't owe this debt that you claim I owe, so delete it from my credit reports and go away. Otherwise, I'm sending the photos I took of my Caller ID unit showing the bogus spoofed numbers you used along with the date and time of the call to my AG. I'll also send a brief but detailed complaint letter to my AG in which I will detail the times and dates you called. I'll let them sue you for a million dollars."