Interesting article on it: https://stopthefud.wordpress.com/2018/02/04/tether-controversy/

Tether and Bitfinex have been surrounded in controversy. Is it fact? Is it FUD? Find out as we analyse this mystery.
Before digging too deep into the FUD surrounding Tether (USDT), you need to have a basic background of what this cryptocurrency is.

Founded in 2015, Tether was created to be a stable coin and connected to the online exchange Bitfinex, one of the largest exchanges in the world. Tether is meant to mirror the value of the U.S. dollar, allowing you to convert or “tether” USD to the digital currency.... continued on the link.

What do you think? Is it fact? Is it FUD?