This whole thing is weird. Bloggers in a specialized subject area will all pretty much write about the same subjects and the same news. The blogosphere is big, but the more specialized the subject, the smaller will be the group of active bloggers. We usually mention where we first saw some bit of material. It’s not only courteous, it encourages reciprocal behavior. Genuine scoops are rare, and creeps who steal material without attribution are also rare.