Gaming Google Trends
How did this happen, you ask? Well, here's my hypothesis on how it could be accomplished:
First, the attacker would need to come up with a unique phrase, something that doesn't normally get much search traffic, so that Google will see a huge spike in activity for the keywords.
Next, the attacker needs to get a lot of people searching for their target phrase. The easiest way to do this is via Social Engineering. Perhaps they jumped on a few popular chat rooms and typed something like this: "If you search for ǝlƃooƃ noʎ ʞɔnɟ on Google, you'll see a scary face pop up!"
Now, if the attacker was really smart, they would make sure their page was indexed at #1 for the keywords ahead of time (easy to do if you choose unique keywords). That way, they could capitalize on the huge influx of traffic they'd get from being #1 on Google Trends front page...
Interesting, Verisign did the same thing back in 2003 with Site Finder. Their efforts were quickly put to a stop due to a huge number of complaints and lawsuits.