Recently I have had a couple of my posted responses removed from the threads I placed them in.  Common theme would be that they were not in fact a comment I had made but where in response to another's, who I am sure other users would see as them being a "troll" or "negative".  None of it is greyed out on my end, just completely gone.  Was the original commenters post deleted and subsequently all others who replied to their comment or something different all together?