I don't think you can infer that they "keep doing it" from additional attacks being revealed, because they all seem to have happened roughly during the same time frame, but are reported with varying delays.

Lawyer here: No. Not criminally. Knowledge that a certain result is likely is not the same as intent to cause the result. This is basically the difference between recklessness and intentionality. Doing something when you know of a likely result is reckless, but not intentional. Only doing something, trying to cause a result (likely or not) is intentional. In this case, the CFAA only covers intentional access without authorization, not reckless access without authorization.