Could I "blog this" any photo of any authors on my blog whitout explicite permission?

(O)eil (O)uvert says:

in short : yes you can.
you could even if people have disabled the "blog this" function.
you could even if people have disabled the "all sizes" function. ?this as implicit encrgmt downloadg?
when you post a photo to flickr, anyone can blog it.

Some people don't mind being blogged, others are angry, and others are happy.

--Where things get fuzzy is at the line between "good manners" and "legal."--
There is no fuzzy line : blogging a picture is considered as "fair use" (in USA, where eg flickr and some blog systems are hosted), so you do not need to ask for permission at all.