This is because people are requesting collateral of greater value than the loan and just running off with it, correct? Hope you "older" users are willing to take up all loans then, since it is idiotic for people to lend out for no collateral.
It's because a common scam is to create a brand-new account and offer "loans" for collateral (a value of which is often a fraction of the requested loan amount). Once you send the collateral, that's the last you hear from the "lender".