There was a live bug today (now fixed) which allowed any authors on a blog to block any commenters on that blog. This is an admin only tool, and has now been restored to an admin only tool. However, if any of you were blocked (your comments will not show up on oppo) today by another commenter please let me or any of the mods know.
What made this especially fun was that you could block someone, but not unblock them (as that role remained with admins).
To be clear, this is different from the bug which currently exists that makes it so that it is difficult to reply, if you are having issues replying, try clearing your cache and see if right clicking on the discuss and opening a new window brings up the mobile editor. If you can comment this way, then you aren't blocked. Then you will need to clear your cache entirely and try again.
If you believe you were blocked and can't seem to comment, you can always reach us at firstname.lastname@example.org or contact us on Twitter.