I noticed over a week ago that nearly all of my ink was gone. Checking my ink transaction history, all of my non-bonus ink was donated to a creator that has been inactive for two years. I'm guessing it was some sort of password leak as I could see others suddenly donating large amounts to that creator on that same day.
I sent in a ticket about the situation, but I still have not received any updates or notification that they were working on my issue. They said to expect an reply within 24-48 hours, but I'm not sure how long I should be expecting to wait.