Hmmm! A subject near and dear to my heart (and psyche).
There are many things in our day to day existence that are annoying ... but unwanted telephone calls are truly frustrating and exasperating ... and they always seem to come while you are in the middle of dinner or are rinsing the dinner plates and your hands are soapy or you just dozed off for a quick after dinner nap. Then there are the incoming cellular junk calls that inevitably interrupt some very important activity or discussion in progress.
I am dealing with this issue proactively. All calls
to my NJ and FL residences and all calls
to my cell phone (and my wife's cell) and all calls
to my dedicated fax number (and my wife's) arrive via VoIP.  : :Yes, all our published numbers are VoIP numbers that are forwarded to the appropriate destination (home, cell, fax). For the extra monthly pennies I spend, it is well worth the cost for peace of mind.
Most, if not all, of the "upscale" VoIP providers we discuss here in the BBR Forums have excellent Call Blocking (Blacklisting) features, with a host of options in dealing with unwanted calls.
For example, Voip.ms and CallCentric gives the choice of blocking/redirecting a specific incoming CallerID or a block of CallerIDs (using wildcard "x" or "*" to replace one or more parts of a DID) or an entire rate center/exchange or an entire area code. PhonePower (one of my former providers) and VOIPo have decent Blacklisting features (but the latter is very difficult to navigate and is not intuitive).
The various Blacklisting options can be customized for each blocked DID (or number groups):
• Hangup.
• Call forwarding to "silly" phone numbers (such as the "Psych Hot Line" at 218-488-1302).
• Call forwarding to "silly" SIP-URLs (such as "Laughing Monkees").
• Recorded voice message.
• Busy signal.
• Number not in service.
• Number has been disconnected.
• DTMF test.
• ECHO test.
Over the past year I've kept track of unwanted calls ... that is, I've recorded the phone numbers, the callers (which I can determine either from the CallerID record or from an online search), the organizations represented, and the frequency of repeat callers.
Some examples:
• MEDCO was calling on a daily basis;
• University of Phoenix;
• Lyndon LaRouche;
• Fraternal Order of Police telemarketing;
• Various collection bureaus (And I don't owe anything to anybody ... except my second grade teacher Mrs. Johnson who lent me a nickel for lunch in November of 1949;
• Various charities ... almost all of whom have never received a
dime from me, not even the March of
Dimes;
• OnStar;
• Comcast telemarketing;
• Alumni organizations;
• Surveys ... every time I have one of our cars serviced by the local dealership, I get a cellphone call from a Virginia area code asking questions about my recent servicing experience;
• Mausoleum and Headstone (Monument) providers ... following my dealings with them for recently departed family members;
• A variety of "empty air" calls where there is nobody there ... even when you listen for 10 or 15 seconds for callers using robodialing;
My methodology:
• I block all Toll Free incoming: 800xxxxxxx (or 800* depending on the provider) ... and 888, 877, 866, 855, 844, 833, 822 for good measure;
• For area codes that I would never expect a call from, I block the entire area code: e.g., 208* (or 208xxxxxxx);
• For rate centers that I would never expect a call from, I block the entire rate center: e.g., 701454* (or 701454xxxx);
• For a range of DIDs that I do not wish to receive calls from, I block a range of numbers: e.g., 70145412* (or 70145412xx) ... when particular nuisance callers tends to use closely related numbers for their CallerID;
• Obviously, for areas of the country from which I receive lots of legitimate calls, I will block the specific DID of "bad people". For example, I now block my
recently departed son-in-law's mother ... by
recently departed, I mean that she moved to Chicago. She is
sorely missed ... or is it that I no longer have the soreness in my rump from this PIA?
Lastly, I continually update my CSV listing which allows me to upload the lists to some of my providers.