My guess is that Wall Street Journal didn't want to pay the prices the publisher (of the scientific journal article) is asking for permission to reprint the pictures, or something like that.
"PLoS is a nonprofit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. All our activities are guided by our core principles." Do you know anything about the Public Library of Science??????
"Aww, if you make me cry anymore, you'll fog up my helmet." -- "Visionaries" cartoon