Copyright and Fair Use

I just read Copyright and Fair Use. This seems to be a pretty good source of information regarding the laws. They seem to be pretty specific in what is considered legal. I know that I have seen many productions that have used pictures, video, or music outside of these guidelines on the internet. Do every day people get charged for using someone else's music in 11% of their videos? I wonder if digital media has brought in a period where it is too difficult to prosecute every instance of "copyright infringement" based on these policies.