It would be interesting to find out what happened here. While the suggestion that there could have been some kind of cyber attack could be true, nobody on this thread has reported anything consistent with that (e.g. having their password changed without their knowledge, having points stolen, etc), and if Velocity had info about accounts being compromised, wouldn't they be forcing password changes in response? Again, that doesn't seem to have happened here.
Additionally, this all seems very reminiscent of previous examples of Velocity conducting a mass crackdown on alleged breaches of T&Cs. There have been suggestions in the past that they have been very heavy handed in doing this - e.g. suspending accounts before they even investigate, rather than in response to evidence suggesting wrongdoing.