Red "unread" indicators on the "All Communities" page should not include posts that have been marked as spam and are invisible to you.

I'm heartily sick of seeing "unread = 3" on a community only discover when I click through that there's nothing new there at all, at all. I think it's caused by some sort of caching algorithm that doesn't decrement the counter when a post gets marked as spam, but maybe there's something else happening.