So, HF 23 on Steem was highly contentious. It took 23.6M steem from 64 users, and it sent them to @community321. What appears to be a white hat action then took those funds from @community321 and transferred them to bittrex with the memo "these are funds stolen by steem witnesses using HF23 May 20th 2020 - please return them to their original owners prior to the fork :)"
That's not a normal memo to bittrex. That's not going into a personal account. Someone is trusting Bittrex, which keeps showing that they are an awesome exchange, to do the morally correct thing and return the stolen funds back to the 64 accounts that were stolen from. If this was merely theft of those funds to a private bittrex account the memo would have been something like 35234ssffds234 as an account instruction, but the text message puts it as a funds transfer to bittrex without instruction to go into an individual account.
What will bittrex do?
Someone either as a white hat hacker or as an inside job got access to the @community321 accounts, transfered the steem to bittrex, and is expecting them to not just keep the steem but disperse it back to the original owners. What a crazy story!