They had time to roll out this bad news..and they have botched it.
Just assume you have been compromised and take appropriate action.
Credit freeze is best option. The lenders you have debt with will still be able to access your information but should deter any new credit in your name. Probably not fool proof
Discover has a service that alerts you to use of your SS if you have a card with them. Something about searching the net for your number. Not sure how it works.
A couple of years from now you might get a $5.00 check from Equifax in a class action settlement
More likely, lawyers will get tens of millions and those adversely affected will get a coupon for 10% off your next purchase at Burger King.
I did the same a few years ago after I received several unsolicited copies of my previous years tax returns. Seems to work well so far, I lifted temporarily last summer for a cash out re-fi. Cost $10 but no other drama to it.