The increasingly popular and destructive hack is a smart trick used by cybercriminals who persuade cell phone operators to transfer telephony services to a SIM card under their control. Europol has recently arrested 26 people due to a robbery of EUR 3.5 million during the transfer of phone numbers of users through an attack involving the swap of SIM cards.

https://thehackernews.com/2020/03/sim-swapping-fraud-hacking.html