you can only delete, not edit anyone else's response.
little-whip ... I meant the thread itself could be 'edited' through selective removal of comment/s, thus altering its whole direction and meaning, not necessarily each individual comment's wording.
As for 'not seeing what I see', I [for a totally unrelated reason] recently checked when I first formally acted as a 'moderator' on the site - and found a 'rejection email' dating to July 24, 2001, so, yes, it's quite likely I have seen things here you may not have.
All site administrators have had [and still have] the power and authority to 'edit' a poster's comment/s, answerable only to the sites' owner/s, and not directly to the members themselves.
On the rare occasion it has been deemed appropriate to do so, though as both JU and WC, etc have matured [as have their members] the incidence of this has diminished dramatically to next to zero, a testament to the careful handling of those whose sole intent was to disrupt and antagonize all and sundry.
The only threads deleted from public view here in the past 6/12 months have been hiccups of multiple postings...where the second to Xth were redundant, or they were spam-bot postings of "Buy your viagra/cameras/meds here...." - things no-one wants or needs....