Barriers to posting SSN-like data would make it difficult for a lot of people to do their job. Software that handles SSN info should have fake data for tests.
Detecting SSNs is hard without accepting a high false positive rate. Much harder than phone numbers, credit card numbers, or cloud credentials.
You can also try to guess is something is a list of SSNs from the context.
Any 9-digit integers are immediately suspect under this reasonable storage choice.