have they released any details of how it happened? I don't understand how is it that difficult for exchanges to keep coins securely,?
Not in full details but you can see the response from binance here:
https://www.binance.com/en/support/articles/360028031711Security on exchanges is obviously very important, i'm sure the security team of binance trying their best to make all your coins safe in binance.
They are now trying to forget this ridiculous nightmare by them. It is almost ruining their reputations but now Binance was back and it works fine now so I think they are now building up their security system not to bypass by a scammer. Thousands or even millions of traders using Binance and maybe us here majority is Binance users I think they are doing their best to keep us safe even the hacking incidents already happened but doesn't give bad effect to the market.