Random Firefly Board shared with me

Hello,

Only asking this for possible security reasons due to my position. I have never used Firefly Boards but noticed back in May that one had been shared with me. It also has a comment from July. Is this a default example board or something? How did it get shared with me? I have never clicked a link or anything.

My Adobe account is secure and only has login sessions I am familiar with, but either way this is unusual behaviour to me. Anyone have a clue as to how this is possible? Also just my opinion but the content of the board is just uncanny and grossly unsettling. 

I have clicked “Leave” so many times yet it is still there.