I didn't have problems signing up but according to them I have tax liens from before I was even born. I went to Experian directly and they don't exist (nor have I ever heard/seen such). Maybe they are trying to be cute with data and supplement it?
If you don't have enough info in your credit report to ask enough questions of course they have to supplement it. you would presumably still know the answers since you'd know if you have a loan or not.