Telecom firms are only allowed to use the 140 series to make calls to consumers, however, unregistered telemarketers continue to use 10-digit phone numbers, making identification a challenge
The US Federal Communications Commission (FCC) has threatened to block calls from voice service providers that have failed to take action against illegal robocalls
According to the Department of Justice, they carried astronomical numbers of robocalls
Robocalls in the US increased to 5.1 billion in November from 2.8 billion in December 2017