This comment was at -8. Its text was invisible in this thread.
http://news.ycombinator.com/item?id=277053
No problem. However, I expected to see the text when I clicked on the link for the comment. As it is, I can't metamoderate (by upvoting, disagreeing with the -8 if it was in fact unfair) or read an Evil Comment that spawned an interesting thread.
An option to turn off (or adjust) the fading/invisibility for negatively modded comments, or a default to show text when a comment's link is clicked, would leave the current system relatively unchanged but allow determined users to read the forbidden content.