[Air-L] blog photo copyrights

Dear Air-List, I am in the process of publishing a book about blogs and would like to use not just screenshots, but also individual photos taken from the blog. These photos were more often than not, taken by the bloggers themselves and might be considered theirs in copyright terms (although there is nothing to indicate this in the text itself). What are your experiences with publishing this sort of material? How did you proceed? Did you ask the bloggers for permission? Any tipps? I would be greatful for any help! Best, Johanna Roering American Studies University of Tuebingen Wilhelmstrasse 50 72070 Tübingen