This is the same hacker group that performed the Bangladesh Bank robbery, that attack the almost stole 1 billion, the only reason they got flagged was a typo. They did manage to steal 81 million though. Byebit does seem to have bad security though compared to Bangladesh bank.

https://en.m.wikipedia.org/wiki/Bangladesh_Bank_robbery

Even regular banks can be hacked, this isn’t just a crypto issue. Same group that hacked byebit also is responsible for the below:

https://en.m.wikipedia.org/wiki/Bangladesh_Bank_robbery

I don’t think it is a good idea to block twitter completely. Some countries use twitter for official announcements, including emergency warning.