It's plausible only in spirit. An actual listing of terrorists does not have 3 terrorists within a 1-mile radius, and does not need volunteers; the FBI already has such a database. But as recent terrorism has shown, the databases are not be sufficient to prove or disprove terrorism. It's just more security theater.

If the FBI started extending its database to more trivial crimes, like say speeding tickets, then it might start being useful. A law that isn't enforced evenly isn't really a law; it's an excuse for the police to harm people they don't like. Computerized enforcement seems like a good goal to aim for.

How prescient pre-Snowden (2013).