According to a protected disclosure filed with the Office of Special Counsel, Borges told the Government Accountability Project that DOGE officials working at Social Security created a “live copy” of the country’s Social Security records in a separate cloud environment that sidestepped usual security checks.
The group says those lapses put the Social Security information of more than 300 million Americans at risk.


They are definitely not. People consider it increased risk for identity theft if they hear their SSN was stolen and you just cited how people are still using them in part for authentication. They need to be completely useless for authentication
I am making a slightly different point and have a bias to this perspective: https://www.legis.iowa.gov/docs/publications/SD/19230.pdf
I am saying that an SSN can be part of a larger validation scheme, not the only key to the castle. Specifically for government sites, SSNs can be linked to IRS data to verify places of last residence. A person generally needs to verify multiple items that are referenced by the SSN before basic authentication can be established and set by the user. (This is part of the full Authentication, Authorization and Access Control triad.)
An SSN is just a broad level identifier. If you look at many laws around the release of SSNs, the redaction is usually in place to prevent the linking of different documents and other data points.
If I released my SSN in this chat, I could be fully doxxed in a matter of seconds. It’s mainly because there are many legal systems in place that use an SSN as a primary key, of sorts. (It’s a bit more than that, as SSNs can be duplicated in some circumstances.)
So to say, at a high level, an SSN is considered private is absolutely correct. However, it’s so easily referenced and obtainable it really isn’t fully private either.
If I was to generate a full list of every possible SSN in the US (which I have done, multiple times), that list is effectively useless to anyone who obtains a copy of it. So, by itself, an SSN is effectively public.
000-00-0002