Mobile Device Theft Deterrence Act of 2012 - Amends the federal criminal code to prohibit knowingly: (1) removing, obliterating, tampering with, or altering a mobile device identification number; or (2) using, producing, trafficking in, having control or custody of, or possessing hardware or software, knowing it has been configured to engage in such conduct.
Subjects any person who violates such prohibition to a fine, not more than five years' imprisonment, or both.
Exempts the manufacturer of a mobile device or a person who repairs or refurbishes a mobile device unless the manufacturer or person knows that the device or part involved is stolen.