It's not that the exchange itself sold the coins, I believe that it was a hack ,and if it will be discovered to be at Binance's end, then they will return return the money to those who was affected in the hack.
I still think that it was at users end because only a small precent of users were affected, most of the users didn't have any problem, so it's probably a software that only X amount of users downloaded.
I only heard of a few users. We can assume that most of them either don't know or didn't post anything, but still the panic is much bigger than it should be. It's only a couple users on 1 of the exchanges and people seem to be reacting like it was the end of the world. Quick, dump all cryptos because somebody reported their altcoins were sold without their knowledge. Maybe you shouldn't keep your coins on exchanges in the first place?
Also it's not like they lost their money, they had one asset converted into another at market prices. The money did not leave the exchange (at least from what I heard).
You know how the community is and very little things can cause a huge panic. It is good that it was quickly curtailed but it was not even a direct attack on binance anyway, and it was the users that the hackers were able to get their account details, generate APIs from the account in the past that ended up being affected but according to binance, only conversions were done with withdrawals paused immediately thereby affecting even the hacker's funds.