Thanks to this webmasterworld thread
Content writers have found a novel way to trick you into thinking their work is original. Their work even passes copyscape and Google searches ... but it's just a scam as the material is 100% stolen.
How do they do it?
They simply replace a few characters within the text with cyrillic or foreign characters that look exactly like the ones they're replacing.
Just a warning!
That's just one more thing to check when you're buying a "content" site. Have a look at the source code for the text!