Copy/South fights restrictive copyright

Recently, Copy/South was brought to my attention. It’s a research group that consists of people from all over the world. They 

seek to research the inner workings of the global copyright system and its largely
negative effects on the global South.

And in the course, they have produced some very nice materials. There is, for one, a reader containing a whopping 208 pages of discussion on the copyright system.

They also have a neat poster corner, with posters that ask some intelligent questions:

Are we really living in an information society when most information has been
privatized?

The copyright notice says "not restricted by copyright". Question for the legal freaks: Does that mean it’s public domain? Or is it simply an invalid copyright notice that serves merely as a declaration of intent?