technology work? >> hi, greta, thanks. well, face recognition basically takes a photograph and tries to reduce that photograph to a biometric template for searching in a database. so the key is dealing with that photograph, and the quality of that photograph and how much of the face that you see. >> so how precise is it? i assume you have to have a photograph to compare it to. but what's the level of certainty that you can make any identification with it? >> well, it's very dependent, again, on the input, the probe. looking at that picture. if you have a good frontal of a face, you are going to get a very high statistic potential in matching in a large database. upwards of the high 90% with a very small false to separate. that's important. go ahead. >> let me ask but the database. can you go to like all the passports ever issued in the united states? can you use that for a database?