Is it a scam to handle telephone lines in fixed-line telecommunications?

Handling telephone lines in fixed-line telecommunications is not a scam. But there is a voice line VoIP. Driven by interests, some fixed-line telephone business agents transferred the fixed-line telephone lines operated by criminals to overseas telecommunication network fraudsters through network technology violations. To put it simply, fraudsters hide abroad, hire a messenger, pick up a voice line at home, swindlers hide abroad, and use mobile App to remotely control fraudulent calls. Because the caller number of fraudsters is displayed as a local fixed telephone, it is very disguised, confusing and deceptive, which is difficult for the masses to distinguish and easy to be deceived.