The issue of moving fast and some exchanges being closed, is simply blocking a group of people trying to access. To avoid this, we can only rely on decentralized exchanges.
This means that the exchange only works on the controlled smart contract
i don't think so recently bancor was hacked and millions were stolen from the exchange. hackers may have find a way to hack the smart contracts somehow. but it is the fact that decentralized exchanges are much safer than centralized one