Add Wonkette to the list (https://www.wonkette.com/feeds/feed.rss); I can load the feed directly in my browser, but Newsblur reports a 403 (Forbidden) response. This is being discussed in another post.
My guess is that the Newsblur fetchbot has been added to some shared list of malicious traffic sources and is being blocked by firewalls at the sites using that list. The fix would either be to identify and correct the list, or to have each site add the Newsblur fetchbot to an explicit allowlist.