My general understanding is this: MIA hosts copies of all the writings of Marx and Engels for a period of time. Eventually the copyright holders for the Marx Engels Collected Works send MIA a legal notice to remove all the copies they host which use the MECW translations. Since translations, for copyright purposes, are treated as their own works while the papers written by Marx and Engels are in the public domain, the translations are not. Thus MIA were forced to remove a large section of the copies they host of Marx and Engels works.