[greggman3]

This is wrong because many uses of the work, like adding it on the front page your your site with some caption, is a derivative work. Putting it on a page by itself or printing on a t-shirt would not be derivative but using it as a logo with text would.

[lucb1e]

But what is the problem with someone taking your modified (captioned) version and using or modifying it further? Why shouldn't they be free to do so?