I am interested in the mechanistic approach which would drive the interventions by the feds.

* are people suggesting targets? who would that be? is this organized online somewhere?

* is there a 'u-tip' number people can dial anonymously?

* is this based on some metric over feed analysis, and smart tools so there's a threshold test in software and a priority list which is run as a join over immigration status?

I'm not asking people to break OPSEC, this is in the spirit of "how exactly did Hollerith cards help the bad people do the information processing" of past times.