Seems that some ISPs will start modifying pages on the fly, and inserting their own stuff. If you notice the bit about
patents they are referring to
Advertising.
Now if I was doing it, I would take a good chunk of the left side for my advertising and push the sponsored PPC ads off the right hand side.

Google Hijacked -- Major ISP to Intercept and Modify Web Pages.
The ISP simply decided to modify Google on their own, demonstrating a real world example of ISPs Spying On and Modifying Web Traffic
http://lauren.vortex.com/archive/000337.html