Massive Increase in Unwanted Cell Calls

Something happened this weekend — starting on Monday my cellphone has been lighting up with unknown callers — a 30x increase! 
I rarely give out the number so I assume one of the following:

1. Ended up on a cybercriminal call-list because of a Data Breach from one of the few vendors that actually do have my cell number. Might have been Hertz or perhaps one of the databases on Oracle. Could be an unannounced breach. Not sure.
2. Cybersecurity sales vendors, preparing for RSA somehow acquired my number as part of a purchased marketing list (if I ever find out who did this I will call them out and advise everyone to never use their products), making a massive unethical call campaign that I somehow got caught up in.
3. Perhaps a Nation State actor that I perturbed is seeking to compromise my phone. I have been talking and doing media interviews calling out aggressive state sponsored hacking from China, Russia, North Korea, and Iran. The calls are highly persistent, even though they are not getting anywhere. Given the vastly dispersed number range (looks to be a prodigious use of spoofed CallerID numbers) they are determined even though I do not answer. A sales team or criminal should have moved on by now.

I do find it amusing and intellectually intriguing, from a cybersecurity perspective! 

Some details:

- So far I see a 30x increase in calls, all starting Monday
- A huge range of numbers, one after the other but never at the same time
- All the numbers are from the US. Appears to be spoofed Caller ID numbers
- Never leaves a voicemail
- Are not sending SMS text messages — which is interesting…
- I don’t see any equitable rise in email phishing, this is only phone calls

The joke is on them:

1. I NEVER answer my cell unless it is a number I know. Never. I follow a whitelist methodology when it comes to calls
2. I immediately BLOCK the number. Yup, I force them to spoof another CallerID number
3. If a salesperson does cold-call my cell I make a note and will NEVER use their products
4. Shields-Up! Now I am on-guard. 
 — I am paying extra attention to every DM, text, and email. I am even vetting known numbers. 
 — I am double checking all my OS & apps patch levels across my all my PC’s and servers, and will do an unscheduled full backup of critical data (that I store offline is a safe). 
 — Lastly, I am scanning my systems, removing any old or unneeded apps, and scrutinizing every running Process and device on my network.

…these are all things I like to do anyways, so it really is no bother. 

Overall, it has been interesting and I am so tempted to answer a call to just to investigate. But that would be in opposition to what I preach. 
Anyone else experiencing such a flood of undesired calls the past few days?