Content and usage is just the buyers problem?

Firstly I must say that this is by no means legal advice, just my understanding and opinions on some of the aspects of digital asset delivery via the internet.  

Looking around the various Forums and Blogs I often read that the end client or customer is legally responsible for the image, and how the image is used, but what about the image content are you sure that you have no responsibility that you have not already discharged.

There are some sweeping statements which are often used as a blanket response for all types of possible scenarios and image violations, but rarely do the posts and comments question the artists and merchants responsibilities, and was enough really done to protect the interests of the artist, agency, merchant, end client or customer?