SSN's Available Online?

Factual Questions
1

I find that by typing a fairly random 9-digit number into google I get results showing websites which maintain large logs of social security numbers. Many have the holder’s name or address posted along with the number.

I have noticed that some have rather unusual behavior - you can go there once, but if you return too soon the page shows up as ‘broken’

Are these for real? And aren’t they illegal or at least enabling identity-fraud?

2

Once you are dead, the numbers are public knowledge and published. I don’t know of any sites for living people, though.

I use them quite a bit in genealogy to figure out if and when people died.

3

I entered my SSN and my surname and got nothing.

4

So did all the other people on the site!

Really, that was probably not the best thing to do.