Also SSN isn’t that distinctive of a format. nnn nn nnnn. Check bits and reserved prefixes were all removed decades ago when it became clear we’d run out unless we use the whole name space (and even then that buys us to 2100). \d{3}\s?\d{2}\s?\d{4} will match a surprising amount.

Detecting SSNs is hard without accepting a high false positive rate. Much harder than phone numbers, credit card numbers, or cloud credentials.