A common technique for getting rid of the pesky critics is drowning them in "positive" voices. These voices can be efficiently crowdsourced. Just a few examples:
from China: http://en.wikipedia.org/wiki/50_Cent_Party
from Russia: http://en.wikipedia.org/wiki/Web_brigades
from Israel: http://en.wikipedia.org/wiki/Public_diplomacy_(Israel)

In the world of cyberwarfare itself, there are frequent skirmiskes underreported by the mainstream media.

During the start of the Gulf War, the al-Jazeera website was DDoSed offline.
http://www.infoworld.com/t/applications/al-jazeera-hobbled-ddos-attack-495

During the 2008 South Ossetia war, there were attacks on machines in Russia, Georgia, South Ossetia, and Azerbaijan.
http://en.wikipedia.org/wiki/Cyberattacks_during_the_2008_South_Ossetia_war

The row about relocation of a Soviet-era statue in Estonia culminated in a series of attacks on Estoinian servers.
http://en.wikipedia.org/wiki/2007_cyberattacks_on_Estonia

The recent attacks that downed Twitter and Facebook were aimed against a single person (talk about collateral damage).
http://en.wikipedia.org/wiki/Cyxymu

In 2000, Israel's servers got under coordinated attacks of a simple nature.
http://news.bbc.co.uk/2/hi/middle_east/992879.stm
Many other examples come from that unquiet region. The number of defacements of .il websites skyrocketed as an answer to the Operation Cast Lead.
http://www.cso.com.au/article/271961/gaza_conflict_cyberattacks_come_too

Other common pairings in the world of natioinalist online conflicts are China/Taiwan, China/Japan, India/Pakistan, and the Koreas.
http://www.popsci.com/military-aviation-amp-space/article/2009-02/der-cyberkrieg

The conflicts aren't limited to the natins. Corporations are frequently finding themselves on the ugly end of a DDoS. One of the recent examples is Amazon.
http://www.theregister.co.uk/2009/10/09/amazon_cloud_bitbucket_ddos_aftermath/

So far most cases are limited to DDoS and simple defacing, with an occasional dash of espionage. However there is a distinct possibility of crippling or even hijacking even things like power plants and other infrastructure. The SCADA systems are often old legacy crap retrofitted for Internet access, often without considering the security requirements for things exposed to the open Net. *That* could become scary, especially if used as a support in combination with other modes of attack.
http://en.wikipedia.org/wiki/SCADA#Security_issues
An example of an accident involving SCADA was the crash of the Davis-Besse nuclear power plant systems, when the Slammer worm crossed through a VPN from a contractor's network into the power plant (which was offline at the moment because of a half-eaten-through reactor head). The article contains more juicy info about other incidents.
http://www.securityfocus.com/news/6767

There are already some governments hiring students or computers geeks to spy and "clean" the internet.

http://www.nytimes.com/2006/05/09/world/asia/09internet.html

There are also a few conspirations theories about China.
So your idea is maybe more real than you think. :)

http://news.sky.com/skynews/Home/World-News/China-Denies-Internet-Hacking-Network-System-GhostNet-Used-Worldwide-On-Government-Computers/Article/200903415251712

http://www.infoniac.com/news/chinese-hackers-spotted-british-government-attack.html