Currently we are unable to capture automated screenshots of coverage behind a pay-wall. However, we do still gather metrics for your coverage & then allow you to upload your own image.
We can help you quickly replace images using our chrome "coverage clipper" toolbar extension. You can read more about that here. http://help.coveragebook.com/creating-your-report/how-do-i-capture-an-image-from-the-coveragebook-chrome-extension