https://qz.com/1134752/bitcoin-price-fell-6-yesterday-after-tether-reported-a-31-million-hack/

The price of bitcoin plunged by around 6% in the early morning today (Nov. 21) after news broke that nearly $31 million worth of Tether tokens had been hacked and stolen. Tether is a digital token that pitches itself as being a stable cryptocurrency that’s pegged to the dollar, so each Tether token is worth a US dollar.

But Tether developers froze the loot in place before the hackers could cash out. They did this by writing new software that blacklisted the address where the loot was held, and convinced all the exchanges who use Tether to run the new software. This means that the looted funds can’t be moved or liquidated. The move amounted to a hard fork of the Omni Layer protocol, which Tether is built on. For extra safety, Tether says it won’t honor redemptions of any tokens from the stolen funds.