Stop Robocalling Me!

January 1, 2019

Jeffrey Lewis Knapp saves the four to six telephone numbers his caller ID logs each day. At night he seeks his revenge, calling back the people he thinks are illegal robocallers. “How can I help you?” the Arizona-based retiree says he asks the people who answer.

The problem with Mr. Knapp’s approach: He sometimes calls people who didn’t, in fact, call him first. Instead, the individuals he calls are themselves victims of a phone-related crime called malicious number spoofing, in which callers falsify their number to disguise their identities…