@Slow death. The solution is for the exchange to be smarter than the thieves. The thieves will never stop trying as long as there is something valuable in the vault.
Wondering why people put so many btc in their accounts, exchange is good for trading, but not for storing values.
Those
people are called whales. They trade cryptocoins by the 100s of thousands of dollars or maybe more in each trade.
Also, I do not know why a rollback was in the discussion for Mr. Changpeng hehehe.