The reason you get that message (in various screensavers) is that the default XScreensaver configuration points to a URL that is no longer valid. I suppose from the name that it used to point to an RSS feed of news from fridge.ubuntu.com.
You can change the URL, either for fridge.ubuntu.com or some RSS feed, by editing $HOME/.xscreensaver. You'll find an entry there called "textURL" with that obsolete URL. Change it to "http://feeds.feedburner.com/ubuntu-news?format=xml" to get what I think used to be the behavior. You can change it to something else. For example, "http://feeds.feedburner.com/blogspot/gJZg" would get you the Google Research Blog.
If you'd like to make that change system-wide instead of just for a single user, the files you want to modify are /etc/X11/app-default/XScreensaver-gl and -nogl. Values in a user's ~/.xscreensaver would take precedence.
(That's true at least on a modern ubuntu-based distribution; I don't know about others.)
I guess I should clarify that it kinda-sorta depends on your configuration, but you are most likely running gnome-screensaver or mate-screensaver, in which case the above instructions work. If you are unlucky, it could be something entirely different (but you would probably know about it since you did something non-standard). For some interesting background as well as some reference documentation, have a look at www.jwz.org/xscreensaver. (I can't post a link because I already used my quota of 2 earlier.)