This one is interesting: http://sourceforge.net/projects/phorkie/

According to the list it has been specifically blocked. It appears to be a pastebin clone written in PHP.

Almost all of them are pastebin-like sites.

http://atnsoft.com/atnsoft.com/textpaster/ seems very unrelated.

My assumption would have been that a government crawler stumbled upon some messages it didn't like and the sites they were on ended up on the list, but the two sites above would unlikely be affected by this.

Archive.org was probably affected because they mirrored some content of any of them.