How do I block calls from unkown callers?

[KarlTheTruth]

How can I block incoming calls that come up on my phone screen as "Unknown"?

                                 Thanks,

                                        Karl w/a-K

[SuzyQ · Accepted solution]

block restricted and unknown calls - Google Play

There are a number of apps that will do this.

[LARWAI1]

unaccepatble Answer Verizon 

[KarlTheTruth]

Thanks SuzyQ.