''her rating wasn't high enough to suspect her of cheating''
There are many cheaters at all rating levels. I suspect that some cheaters are ''smarter'' than others and don't raise from 1200 --> 2000 in a few weeks or months.
''Anybody want to explain why so many accounts were closed in that one group in a few days?''
They may have all been the same person under separate accounts or they may have all been part of a cheating ring -- i.e. purposeful losing to boost rating, or just a crew of similarly minded cheaters.
People get their accounts closed for cheating (involuntary closures)
...or they close them themselves (voluntary closures).
I doubt there are any alternative explanations.
I recently joined the Chess Queen group. It seems like a real friendly group with lots of posting on the notes and in the forum.
Three days ago the group Super Admin disappeared. Her account was closed. In the group there was no visible reason for the Super Admin to have her account closed. If she was unhappy about anything, it didn't show. Her rating wasn't high enough to suspect her of cheating. A few others in the group had their accounts closed at the same time. One guy claimed that he had reported it to somebody at chess.com, and now HIS account is closed.
People in the group are claiming that it is a rash of hackers going around. Others say that it is a bug related to chess.com V3. It is a mystery to me. There is a related thread in the Off Topics forum, but it seems to me that it should be discussed in this forum.
Anybody want to explain why so many accounts were closed in that one group in a few days?