What's with the people whose screen name is [deleted]?

Who are these people are why are they "deleted"?

It's because their account is deleted, almost always by the user themselves.

We (the staff) don't delete accounts except by request. Occasionally we ban accounts but those don't show up as [deleted].

These are people who deleted their own account. Usually they come back under a different name.

So how are they still able to post comments?

The comment was posted before the account deletion?

I'll swear I've seen new comments appear under that name, but you would know better than me.

I'll swear I've seen new comments appear under that name, but you would know better than me.

I think that's just his or her username. Deleted...is the username.

Chainer can correct me if I'm wrong, but I am speaking from simple observation from a mod's perspective. When a user deletes their profile, the system immediately changes their name (visible to the public) to [deleted]. At this point, none of their comments or uploads are deleted, because in many cases that would be detrimental to the site. After all, why would we want these uploads to disappear because one person (of their own accord) decided to delete their account? And it is impossible to do anything further with a [deleted] account. Now, if HalfKorean has a specific example of

I'll swear I've seen new comments appear under that name

then we would be more than willing to discuss it further.

Right now I don’t see any user by name:

https://www.girlswithmuscle.com/users/userlist/

I'll swear I've seen new comments appear under that name, but you would know better than me.

Maybe the image was merged and so are the comments. This way it's possible that a comment, that you haven't seen before because it was on a duplicate, is later visible after it has been merged.