The thing is, like most message fora, people quote previous posters and they are nested. If I post something and people quote it in response, generally, wouldn't my original text be preserved in their response?
Yes, that's the issue I was addressing here:
If there is a concern about deleting material from our own posts that has been quoted by others and would therefore survive the deletion of our own post, I think that should be handled on a case-by-case basis through moderator intervention (and, in any event, that issue is not limited to user-created threads; it could arise just as easily in a thread created by another poster).
Under the current set-up, outside the context of a thread you yourself created, if someone quotes your post and you subsequently delete your post, the quoted text survives the deletion. So the issue is not limited threads you created, and I'm not sure why your posts should get special protection simply because they were contained within a post you originally created (though it is a good point that case study posts are probably the most likely to be the subject of desired deletion).
If it were possible to create "self-destructing" or "self-destructible" threads, which put responders on notice that their responses will be deleted or could be deleted by the original poster, I think that would be a good solution, but I'm pretty sure that's not technically feasible or practical. If the only two options are either "all users can delete entire threads they created, even if other posters responded in them" or "no users can delete entire threads they created, unless no other posters responded in them," I would prefer the latter, and special requests for moderator intervention could always be made if a poster wants to delete an entire thread they started.
In any event, if the primary concern is protection of users' own content, even the current set-up doesn't totally address that issue. If someone's posts within a thread they created are quoted in another thread (not to mention copied or downloaded to another source outside the forum), the quoted text would still survive deletion of the original thread. There's got to be a reasonable expectation of some level of nonprivacy and noncontrol over information that you deliberately and willingly post on an internet forum. I think having the ability to (i) delete your own posts and (ii) appeal for moderator intervention for any steps beyond that, but not having the ability to delete the posts of other posters, strikes the best balance between the competing interests.
