Law enforcement and mobile carriers (via the GSMA) maintain global IMEI databases. If you write a random, non-original IMEI, or clone a working one, the network can detect conflicts. If you own the device and are restoring your original numbers printed on the box, you are ethically and legally clear.
in many countries. These tools are intended for restoring the device's own original number if it was lost during a software flash. spd 6530 imei repair tool repack