In the following scenario:<p>1) I vote up a comment.
2) Later on, the author of the comment edits its contents.
3) After such change, I don't consider the comment valuable as before anymore.<p>Shouldn't I be able to vote it down? In reality, I am asking if the positive/negative votes for a comment should be rolled back when the comment is edited. It makes sense to me that users vote for a comment in particular, not the future versions of it.
As things stand, no one else knows you upvoted it any way. Better just not to vote for anything, only downvote. It's possible that someone can change a negative comment to make it look bad that you downvoted it but it's a pretty edge case and HN only shows that a bunch of people downvoted something, not who.