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Ah. Thanks for the clarification. I knew posts get hidden like that due to a flag, though not because the rep score was below 25.

I may be wrong, but that's what I've deduced.
It means that those under 25, like @skeptic have to post content to get back up to 25.
Their comments are all hidden until then.

one look at that guy's profile name - "Cynical Asshole" - left little wonder as to why he might be getting flagged and has such a low rep... lol

I may be wrong there. I've just checked his comments tab and none appear to be hidden by default.