In college I lost one of my jobs and knew I needed another one fast or I wouldn't be able to make rent. I spammed my resume on Indeed and Monster.
I got an email offering an IT-adjacent job in town. It was Saturday and they said I could stop by in a few weeks to fill out the paperwork or we could do it over the phone and start Monday. I called so I could get my first paycheck before the end of the month. We eventually got to her asking for my Social Security number and I froze.
I realized this could be a scam, but I was really desperate. I tried to think of a way to test them, so I said that I just realized I would be unavailable during certain hours, would that still be okay? She said she had to put me on hold to talk to the manager. After a while she came back and said it should work, but I would have to discuss the specifics with my supervisor once I started.
That sounded real to me. If it was a scam surely she would have just immediately said my schedule was fine, right? I gave her my SSN. She said I was ready to go and to have fun on Monday. I got there and it was just a parking lot. Couldn't get a response via phone or email.
A couple months later I found out someone across the country had used my SSN and I had to freeze my credit.
The problem is you have to give your SSN for legitimate employers as well. It is mind-bogglingly stupid that there's a magic number you have to keep secret and also have to give to everyone to participate in modern economy.