anything civilian law enforcement agencies can have,so should other civilians without any obstacles other than showing an ID and swearing you are not a criminal,fugitive etc (in all fairness, only states should be able to prevent felons or addicts from owning guns-the federal government was never given such power)
Business, employer....and strangers. Apples and oranges.
With your SSN, anyone can access you bank account as long as they have one of your checks. Or see one of your checks.
There are drawbacks to using SSNs for identification, as we are finding out. But that doesnt mean it's an intelligent move to start handing them out to strangers until more safeguards are in place.
Unless you plan to? If not, why not?