Goddammit! The social security number is not to be used for identification purposes other than by the social security administration. How many times do the witless f*ckers in banking IT need to have that screamed at them? And then, having decided to ignore that stricture, to only use less than half the digits?
Jesus f*cking Christ on a bike.
How in f*ck's name could this level of stupid be deployed in this day and age in light of what we as an industry have learned regarding electronic banking and the methods to subvert them?
To paraphrase the short guy from Game of Thrones:
Hands. Coal hammers.