Quest doesn't ask for SSN - I use them for my lab tests. If you're a collection agency you're going to be getting financial records which are going to include SSN (I assume from the financial reporting agencies) and your job is to connect them to the names of delinquent Quest customers.

So Quest has pretty much no blame here - it's the collection agencies that are allowed to buy people's financial records which include SSNs that are the bad guys here.