The logo looks like something CNN would cook up at the dawn of a new military campaign, but this time the computer-generated bullet holes are in the CNN logo itself.
The text, according to Will's translation, which is about as good as I can do as well, reads: "Rise up! Angrily resist the demonization of the Tibet affair! / Chinese netizens roast CNN and other Western media!"
Here's a good Global Voices post on the general anti-CNN movement, which actually is more generally an anti-foreign-media campaign.
On a related note, I have previously reported on the patriotic "Red Heart China" campaign sweeping the Chinese Internet.
Shanghaiist had perhaps the most visually compelling post on the "Red Heart" campaign. It shows an MSN list full of hearts and a Twitter feed utterly concerned with spreading the word about the pride effort.
All this national sentiment is perhaps not unexpected, and this serves in my mind mostly as an example of the potential effectiveness of online peer pressure. Individuals not especially concerned about recent events may just be going along with the campaign. It would be awkward to be the only person on your friends' buddy lists not displaying the heart.
Sina's imagery takes it a bit further, however. I think it would have been possible to get across the point that CNN's reports have not been always the best informed--a claim I can neither confirm nor deny as I haven't been watching--without seeming to encourage individuals to turn guns on the network.
The story of Grace Wang, told in her own words in The Washington Post, should serve as a cautionary tale.