Cons:

It can identify which carrier (e.g., AT&T, Verizon) the phone is locked to, which is essential before attempting an unlock. Paid Detailed Reports:

A text from an unknown number: "Turn off the phone. Do not connect it to Wi-Fi. Do not charge it. We know you have it."

The Ghost in the Silver iPhone

Checking the IMEI or serial number is essential for several reasons:

Check iPhone IMEI or Serial Number for Any Apple Device - iUnlocker

Instantly see if a device has been reported to the GSMA blacklist.