Cellular Phone Robocalls, telemarketing and annoying calls and scams

Scope

This article refers mainly to cellular phones in the United States. Some of this information may pertain to traditional landlines and Voice over IP services in the United States but my main focus is on unwanted calls to cellular telephone.

The problem

Spammers and scammers can purchased VoIP lines very inexpensively ...

http://consumersunion.org/end-robocalls/problems/

http://www.cbsnews.com/news/robocalls-are-ruining-more-dinners-every-day/

"... complicated mix of greed, technological advancement and laws that don't always discourage salespeople or scammers from calling. While the Do Not Call registry certainly keeps some consumers from getting pestered, the fact is that many telemarketers decide violating the law is worth the risk. Others are located overseas, where it's harder for the U.S. government to track them down and prosecute them."

How to report it

FTC - https://www.consumer.ftc.gov/articles/0076-phone-scams

FCC - https://www.fcc.gov/stop-unwanted-calls

FBI - https://www.ic3.gov

Ways to combat robo and spam calls or text

Although I personally think this is useless since robocalls usually loop through phone numbers anyway ignoring such lists you are encouraged to visit http://donotcall.gov
Block the (displayed) number on the cell phone itself if the caller-id or number reported is not spoofed. Many times it is.
Call screening software on your smartphone (know any?) https://www.nomorobo.com/?
Your telecom provider (AT&T, Sprint and Verizon) block the number on their end. They are very unlikely to do this without a court order.