A security device comprises a portable magnetic stripe reader and computing functionality associated with the magnetic stripe reader, such as a credit card reader, drivers license reader, debit card reader, club card reader, or any other element that can be mechanically read. A single device may be needed for evaluation of each type of stripe carrying product, or a single device may have multiple functions and can be used (with or without switching to specific identification sequences) for evaluation of different magnetic stripe carrying products. It may be used as a law enforcement device, particularly to combat identity theft and financial fraud.