CryptoOracle, Medium's most read crypto blog, was kind enough to publish this article I wrote on the design of tether coins. Summary: Mr. Incredible should not have a cape in his hero outfit, the cape creates a hidden risk. So too, tether coins that keep assets in fiat banks have hidden risks. The article explains the problem and offers thoughts on solutions.
https://medium.com/crypto-oracle/tether-design-no-capes-35db21c395d9