Not enough that artists get gunned down:
... [W]hile glorifying [the French magazine] Charlie Hebdo, outlets are simultaneously thumbing their noses at the cartooning industry.
Outlets quickly aggregated and storified the responses of cartoonists, usually by embedding tweets, without contacting artists to obtain rights. (Two notable exceptions: Medium’s The Nib and Fusion’s Graphic Culture are only publishing work with permission, and they're both paying for what they publish.)
It’s a natural evolution of the digital media landscape, where explainers and roundups are king. This process is also unethical. Cartoonists, especially those who work in the journalism space, are often on the front lines of cultural conflict. They receive threats of physical harm and are often freelancers. They often make very little money for hours of hard work. ...
Full disclosure here, I haven't checked to see if Erin Polgreen's representations above are correct. But assuming they are, this pretty much fits the historical norm. Down through time, cartoonists have often been abused and exploited. And even when they are paid, they're usually underpaid. The killings just take the abuse to a new, horrifying level.
Add On: This might be what Erin P. is talking about. Hopefully, the Wall Street Journal has cleared and paid for the cartoons.