36% interest rate cap

Over at Consumer Rights Watch, Mark Ireland has stated two truths about Payday lending:

1. Payday lending is a business that simply keeps people in debt, rather than provide them with an emergency safety net, and

2. Only enforcement of a comprehensive interest rate cap at or around 36 percent for small loans will solve the debt trap problem.

We can play around the edges or go to the heart of the matter. Is it ever moral to lend money at unconscionable rates of interest to people who are struggling and in such dire need that they will borrow $300-$400 at 390% or greater? Why is loan sharking by an individual any less insidious than loan sharking by a corporation?