Molto semplicemente, perché gli standard per le reti mobili richiedono che l'IMEI sia univoco . Consentire agli utenti di modificarlo violerebbe gli standard.
The International Mobile Equipment Identity number (IMEI) uniquely
identifies an individual mobile station. The IMEI is unique to every
ME and thereby provides a means for controlling access to GSM networks
based on ME Types or individual units.
L'assegnazione dell'IMEI è strettamente controllata :
The term Reporting Body shall refer to a Body that is recognised by
the GSM Association as having authority or competence to allocate
IMEIs to ME Types. These Bodies may have also been given authority by
their national governments or industry bodies to perform a regulatory
conformity assessment procedure or otherwise permit the use of mobiles
on networks. There may be more than one Reporting Body in a country.
(fonte: link )
Inoltre, alcune giurisdizioni richiedono che l'IMEI sia utilizzato per bloccare l'accesso alle reti mobili e rendere illegale la modifica dell'IMEI :
Re-programming mobile telephone etc.
(1)A person commits an offence if—
(a)he changes a unique device identifier, F1...
(b)he interferes
with the operation of a unique device identifier.
[F2(c)he offers or
agrees to change, or interfere with the operation of, a unique device
identifier, or]
[F2(d)he offers or agrees to arrange for another
person to change, or interfere with the operation of, a unique device
identifier.]
(fonte: link )