Google accounts for 6% of al internet traffic globally

"Five years ago, Internet traffic was, for the most part, managed by tier 1 providers like AT&T, Verizon, Level 3 Communications, and Global Crossing, all of which connected to thousands of tier 2 networks and regional providers. Today, that has changed. Now, instead of traffic being distributed among tens of thousands of networks, only 150 networks control some 50% of all online traffic. Among these new Internet superpowers, it's no surprise to find Google listed. In fact, the search giant accounts for the largest source (6%) of all Internet traffic worldwide.
This data comes from a new report put out by Arbor Networks, who has just completed a two-year study of 256 exabytes of Internet traffic data, the largest study of global traffic since the start of the commercial Internet in the mid-1990's."
Source: Arbor Networks report, cited by the New York Times, 13th October 2009
Note - In the original press release here it says that 30 large companies make up 30% of the traffic, and mentions Google and YouTube individually, so this 6% presumably refers to Google entities, and not owned services like YouTube and Blogger