It's no secret that the French news media are subsidized. "General-interest newspapers" ranging from Le Monde to Humanité receive tax breaks that help keep them afloat. For exact figures on the size of these subsidies, you can refer to Julia Cagé's Sauver les médias (Harvard will publish my English translation next year). But it seems that the authorities are reluctant to extend this advantage to the new online media, at least in the cases of Médiapart and Arrêt sur images.
Now, it may be simply that the tax authorities and legislators are slow to catch up with the changing realities of the media and the increased importance of online versus print. Or--a more sinister interpretation--it may be that the authorities are reluctant to support iconoclastic and critical news outlets that often take the lead in exposing government malfeasance, as Médiapart did when it broke the story of Jérôme Cahuzac's tax cheating or beat the drums regarding campaign finance law violations by the UMP and/or Nicolas Sarkozy. Are we witnessing backwardness of retribution? Hard to say, but in either case the consequences could be serious.
Médiapart is inviting concerned citizens to help by contributing money to keep it in business. If you're interested, you can use the site jaimelinfo.fr. I did. But be forewarned: the form insists on knowing your country of residence and will accept only "France" as an answer, and when I clicked to pay, I immediately received an e-mail from my bank suggesting that someone might be misusing my credit card. But my contribution appears to have gone through.