Why Is A Group Discussion Closed Without Explanation?

In a group I administer, I maintain Discussion threads for an Archive by subject matter for group members when their work is removed from the Features page (and for convenience of searchers too). I encountered a weirdness today, that some discussions were closed without my knowledge and without contact with me or any explanation. As far as I can tell there was nothing offensive about the threads I maintained (with a lot of time and effort in order to benefit both artists and searchers of group specific art and photos).

I have been searching discussions today to see if I can "get a clue" - all I found is that in response to someone's similar question about a year ago on the mysteries of unannounced closed group discussions, I found this response:

"Isabella Abbie Shores Isabella Abbie Shores10 Months Ago
i closed it.

You started a thread against members who upload public domain images. You are not allowed to open threads to have a go at other members. You were told clearly that they are allowed to do it in that thread.

when a thread is closed you do not reopen it."

My Questions now after reading that are below (because the response made no sense to me):

(1) Why is my posting of the thumbnail of group images linking to the member artist's page in a discussion thread wrong? People do it all the time on FAA/Pixels !! I get a million emails a day doing same thing from FAA groups, usually called the "Thank You" threads.

(2) What does the response mean when it says "a thread against members who upload public domain images" - I don't know if it applies to me, and even as I write this, I think maybe that was specific to the person a year ago who had asked about their discussion thread.

(3) Is it wrong of me to try to help out members/public by creating discussion archive threads by subject matter when group features are removed from the main group page? I have seen no "rule" on that. And it was weird that not all my similar discussion threads were closed, just one or two that I found so far - I have not checked all the threads.

(4) Is it possible for you to tell people why their discussion threads were closed when you do it - because I am thinking of just starting a replacement thread so I can continue with my archiving method of the older features on the main page. (I do the archiving before removing featured images on main page.)

Would appreciate some info or feedback on this.

Thanks,

Bonnie Follett

http://fineartamerica.com/groups/san-francisco-city-by-the-bay-art.html