Did you know that without unfriending them completely, you can keep certain annoying Facebook friends from cluttering up your wall by hiding them? To hide a friend named Tom (for example), simply move your cursor to the X in the upper right-hand corner of one of his updates, and then click “Hide all by Tom.” To unhide them, go to Edit Options (under Most Recent) and click the X next to their name under “Hide posts from.” For details and screenshots, read Ask Dave Taylor.
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Tech Tips » Facebook » How to Hide Friends on Facebook
I think that your post is simply hiding the wall posts of such annoying friends. But I guess it also helps to avoid being irritated with those annoying friends.