IMPORTANT.
Something strange is going on, some memo/member addresses are being emptied to a single address.
DO NOT LEAVE LARGE BALANCES ON YOUR MEMO/MEMBER ADDRESS.
Thanks to spice trader for spotting this.
I don't understand though, wouldn't the bad actor need your private keys or something to empty your wallet? Forgive the superficial understanding, I don't see how it's possible.
Yes, the theory is that they may have acquired them via browser cookies or something else in browser addons per Geri's post. It is unknown if Memo itself has a exploit.