Be aware that Called ID can be Spoofed... so the caller may not be someone that you know or expect to call you. Both the FCC and the FTC (among other experts / trusted sources) have warned about this.
NEVER give personal information to any "caller" (if they insist on it... lookup the phone number of the Bank, Vendor, GOV'T agency and CALL THAT NUMBER before surrendering any info). Tell youngsters to NEVER give out any info as well.
Third - my solution to the problem of annoying callers/texters:
1. I used to NOT answer calls from anyone not in my CONTACTS list, but I would lookup the number online and BLOCK them from ever calling/texting me again. That worked, for a while, but soon became almost as much an annoyance as getting the calls. (some people may not be able to take this approach... particularly those that MUST take calls from customers/potential-customers)
2. So... I decided to just NOT answer AND not lookup numbers for such callers/texters.
But the phone always "sounded an incoming call or text notification". I decided to employ the DO NOT DISTURB (DND) feature on my cell phone (no landline here).
I enabled DND and went through the menus/options which allowed any CONTACT to "ring through a call/text" and also to allow any alarms which I had set to sound at the appointed time. But all callers/texters NOT in my contacts list NEVER "sound" a notification.
Yes, their TXTS still come through (but there is no "notification" icon). When I get around to looking at TXT messages, I simply delete those, unread.
Yes, their CALLS still are listed in the log as a "missed call" but no notification is ever issued when they call.
If you should look into trying something like this... be aware that not all Operating System Versions have the same features/options. And, I refuse to download an APP that might "screen" my calls & texts ... it's simply none of their business as to whom I allow and whom I reject.
FWIW and YMMV
While on the subject of ANNOYING calls, did you know:
All I have to do when I get a junk call on my cell is pull up the number, then hit block.
MAKE AMERICA DECENT AGAIN
Yes Dixie, I could do that as well. In fact; I used to do that.
But the question (for me) became WHO is managing such a feature? I always opt for the most BASIC plan (had Verizon for years, but dropped them and now use AT&T's Cricket). I have unlimited DATA/TALK/TEXT for $35/month. I don't use a lot of their Network's DATA, but it is nice to know its there when needed (for example: tethering my laptop to the cellular network when "on the road" and no Secure WiFi is available).
Verizon used to have that capability (blocking numbers) BUT for an additional monthly charge... for blocking up to 10 numbers (don't know what they do now). Cricket has that capability for up to 100 numbers. In both instances they use a FIFO (first in, first out) and/or AGE (after so many days the blocked numbers age-off that list) method for enforcing that limit. At any rate; THEY KNOW (data mining) who you are blocking and who you are allowing. KEEP IN MIND that Caller-ID can be spoofed... so once "they" (especially so-called "free" APPS) know, who you are allowing, that info could be used for nefarious purposes.
Using the DO-NOT-DISTURB method allows ALL calls/text to reach you (you just don't get SOUND alerts)... so no data mining can be used to discern who you allow/block. Well, except perhaps when other APPS obtain "permission" (quietly, in the background--when installing themselves) to access things which they really DO NOT need access to (such as; Contacts, SMS, Folders & Files, Camera, What other APPS you have on your device, etc.). I always CHECK & DENY "permissions" (via Settings > Application Manager) whenever I am installing/testing APPS.
Then too, there are many APPS (lots of "free" ones) which offer to MANAGE your calls for you. Sorry, there is NOTHING FREE... and in this day & age of rampant Identity Theft that is doubly true. For they too use data mining to peer into your private life and share/sell (or otherwise misuse) that info.
In any case; I filled my 100 blocked numbers list to overflowing, many times (I've had the same number for decades, it was a landline that I ported over to my cellular service). I have 100s of "contacts" and I am interested in hearing ONLY FROM THEM. The rest of the "unsolicited calling world" can go to hell--I'm not interested in whatever it is they are soliciting (Medicare Supplemental, Polls/Surveys, Phishing & Scams of all sorts, etc.).
So, bottom-line... DO-NOT-DISTURB works great (they way I have it configured). It only takes a few moments to ENABLE & Configure D-N-D. What others choose to do is completely up to them.