[mudkip]

When you interact with a piece of content owned by someone else (or transfer ownership of your content to someone else), you shouldn't expect to retain full ownership of your contributions. If I make a post and then delete it, all comments (from everyone) should be deleted because the parent object is now gone. However, if Bob makes a post on Alice's Timeline (e.g. a Happy Birthday message), Bob shouldn't expect to fully control that object anymore - Alice's friends can now fully see that post (regardless of what Bob's privacy settings are set to). In fact, if you look under the hood at Facebook's DB, you'll see that the row that Bob created has ownership transferred to Alice (AUTHORED_BY/AUTHORED <-> Alice), with a secondary pointer to Bob that's used to draw the "Bob > Alice" text.[0] Bob should not be able to delete this anymore because he no longer owns the object. You can argue that Bob should maybe still be able to edit the content (and replace it with something new), and I wouldn't disagree, but Bob should not be able to delete the fact that the row ever existed. Comments on someone else's post by a comment author that deletes their account should be transferred to a [deleted] account, because that maintains the integrity of the discussion for everyone involved - it just drops 'who' wrote a particular line of text. If you want to literally replace all of your comment text with something like '-', I'm not going to argue with that desire (or suggest you shouldn't be able to do it). However, it's insane that the rows themselves disappear, because there's no indicator that anyone else ever participated in that discussion (and thus most old comment threads appear schizophrenic).

[0] One hilarious side effect of replacing the object's ownership is that technically, all of the messages Alice received wishing her "Happy Birthday" appear to be written by herself. You have to find the additional TAO edges to reconstruct the true post author.

[dwild]

> If I make a post and then delete it, all comments (from everyone) should be deleted because the parent object is now gone.

Why does the ownership start at the post level and not the comment? If you consider that comments shouldn't be removable, that the post is now the owner of its child, what about the higher hierarchy. Is the forum category creator is the owner of the post too?

> However, it's insane that the rows themselves disappear, because there's no indicator that anyone else ever participated in that discussion (and thus most old comment threads appear schizophrenic)

If the cost of staying owner of what you post is a few comment threads that "appear schizophrenic", it doesn't seems like an high cost to pay.

[mudkip]

There are some valid points to keeping comments for posts that have since been deleted, and I don't necessarily disagree with them. For the sake of simplicity, however, I'm assuming that all of the comments on a typical Facebook post aren't going to be relevant if the post itself is deleted. On Hacker News, however, if the URL for this post stopped working, I think it's pretty clear that the discussion below continues to hold merit.

The ideal solution to comment threads would be to replace the usernames of people who simply delete their account with [deleted], but keep the content unless someone explicitly overwrites it. The biggest issue isn't that the content is gone (any given comment), but that nobody knows how many things are missing. It would be much better (with no loss in privacy) to at minimum just replace those comments with null text and a null owner, to at least show that 3 rows used to be here, between these existing rows.

[dwild]

> There are some valid points to keeping comments for posts that have since been deleted, and I don't necessarily disagree with them

Then your argument isn't about parent-child relationship, but value of the actual content. I can assure you, even if you don't give it value, there's one.

The funny thing, this is most probably why it's important to delete it if someone want to delete his content. It's his value, not yours, not Facebook's, no one else.

> It would be much better (with no loss in privacy) to at minimum just replace those comments with null text and a null owner, to at least show that 3 rows used to be here, between these existing rows.

I don't care about this.