One of the times I answered I told him to put me on the do-not-call list and the live person said: "FUCK YOUUUUUU" and hung up. My calls increased considerably after that day. Yes I have considered suing many times, but chicken out realizing how much work would be involved. Most of the calls don't ring anymore as I migrated to Google Voice and just turned on Do Not Disturb for everyone. I can read that it's telemarketing spam or someone that's real.

Regarding spoofing - 100% are spoofed now. In the last 6 months all of the spam calls I have in my GVoice inbox match the same first 6 digits of my phone number. The last 4 digits are random numbers.