4Chan has been notorious at trending topics on Google Search for a long time now. Google Trends basically track number of searches made for a particular term and then automatically pushes it up the trends if there are lots of searches happening for the same topic. Once a search term enters the trends, it can be viewed at http://www.google.com/trends/.
Many of Google search trends in the past have led to nothing and instead are some sort of pranks played by 4Chan Anon users on someone or the other. Quite recently 4Chan Anon members started to attack several big sites including MasterCard, Visa and PayPal among others for Operation Payback for Wikileaks.
Boing Boing did a good post on the tools being used by them to carry this attack. In that post, they had a link to an interesting image on how 4Chan wanted to spread rumors of it having access to Credit Card numbers of MasterCard users which can be viewed here. In that image, there was a section where instructions were posted on how to get into trending topics in Google Search.
Google search "MasterCard deemed unsafe". Go to RefreshThing.com. Paste Google search URL into url bar. Press Go!.
Doing this will automatically increase the number of records Google gets for a particular search and then get it into the trending topics and to the eyes of more users. This is not the first time that Google search trends have been gamed and it has been methodically carried out by lots of users in the past. However, 4Chan definitely has the clout to get it done. Such trending topics are also a cause for a lot of spam in Google News.
4Chan Anon group has definitely become quite an influence on the Internet and have probably reached a place of dominance where they can control it. Whether it is right or wrong is for you to decide.
I have contacted Google on this issue and am awaiting a response from the in this matter.