It has already been mentioned and also the White Hats didn't stop anyone. The hacker got away with $30 million. Initially he used the exploit and moved roughly 28,000 and then almost a day later he had used the exploit to move funds from the 2 other accounts. Also most of these White Hats were probably from Parity trying to limit their fuckup.
That sounds pretty bad for Ethereum. It should make any serious investor wonder what other vulnerabilities are out there that could still be exploited.