US-VIST is designed to stop visa fraud.
When an applicant applies for a visa, their fingerprints and photograph are taken.
When a person enters the US on a visa, we take the persons fingerprints and photo and US-VIST checks those against the fingerprints and photo of the person that applied for the visa.
US-VIST takes the human error out of visa fraud. A human will almost never be able to detect a good counterfeit visa (the kind the terrorist use), while US-VIST will detect it 100% of the time.
The Mexican Border Crossing Card (visa) is the most counterfeited US visa.
While I understand that this will cause delays, what is more important to us, our safety or the appeasement of Mexico?