Actually this is one of the myth's of the internet, just becuase it is publicly accessible DOES not mean it is public domain. Sorry no links, because I'm at work. (I've done a lot of copyrighy law and technology research for my biz law class). Some law was passed in 1989 which basically attached copyrights to any form of communication. Look at a public library, everything is freely available to the public, but you can't check out a book of poems by Robert Frost and say you just wrote all of these and try to sell them.

Doubly wrong is Pepsi (or their retarded web design consultants) who took YOUR image, modified it and are trying to pass it off as their own. If I took a Pepsi logo and used if promotion for MY own personal gain, I would be in the wrong, as is Pepsi right now.

Look at this in a real world context. You took a photo of your car, someone found it on the street, took this photo and used it in a national advertising campaign, all the while saying it was their photo, and their car. Here you can see, it's definetly their bad.

If you it REALLY bugs you, do something about it.