Comment by snowwrestler

Social Security receives payments as well as makes them. SSNs are keys for both.

The “super old person” SSN numbers are in the DB mostly because non-citizens are using them to pay into the system. If you delete those numbers, the next payroll run will inject them right back in.

And you would remove important accounting metadata for each payment. Metadata that is consumed by the systems that prevent fraudulent payments from going out.

The only way to stop the fake/bad SSNs is to go into the field and address each instance with employers. This is time-consuming and expensive, which is why no one has done it much.