A lot of this would be very labor intensive and would likely require warrents. I think people understate the magnitude of all this.
Funny thing about computers, as most people who've used on knows.
You only have to tell the computer that "A2 divided by (b2 x $c$1) - 1 " equals the margin of safety once, and then copy it down for 16000 rows, if you want. The computer does all the work.
For today's day and age...
All LEGAL residents have their Socialist Security Number in the 'puters, along with their address and full employment history.
All LEGAL residents have their tax returns, which includes their SSN, in the 'puters, along with their address and other identifying info.
All LEGAL residents with drivers licences have their current address and their SSN, and biometric ID info, including thumbprinting and their need for glasses.
All LEGAL residents have a credit history that references their SSN, their addresses, and their spending habits.
All LEGAL residents that have cars have that information in the national databases, also.
All LEGAL residents that have telephones have their SSN's and credit histories attached to their phone use data, as well as their residences.
All LEGAL residents who have cable TV or other non-broadcast recievers, have that information tied to their SSN and credit history as well.
All LEGAL residents accessing the internet have their ISP tracking them.
All LEGAL residents who have bank accounts have their SSN's on record as well as all of their non-cash purchases.
All LEGAL residents from foreign nations have their information on line with the US State Department.
ALL that data is in the computers right now.
Writing the program to connect employee applicant Joe Blomez with the SSN he provides and his given address and other info is a matter of writing a computer program and getting out of the way. The Invader leaves a footprint, too, but it's his lack of a legitimate lawful footprint that can be best used to find and arrest the criminal alien.