There is a huge difference between taking a loan "on someone's behalf" (as their representative, eg by someone with power-of-attorney) versus via impersonating them. The former is rare but legitimate; the latter is fraud.

It may be fraud, but if it's possible, that's still a problem.

SSN can not be used as authorization, because it isn't secret information. And really, the same is true for credit card numbers; they're shared with too many parties to consider them secret.

I mean the latter. Changed "a loan on you behalf" to "a loan accouted to you"

Yes and outside of the US nobody would be able to do a loan with a power-of-attorney without showing evidence of it