But, instead of attempting to define sonofabitch, (here's dictionary.com's definition) I will provide examples through photography. Yes, a picture says a thousand words.
In the first example, the man on the right is attempting to disarm a bomb. The man on the left... well, he's a sonofabitch.
In my second example, (thanks to Kim's query regarding a certain picture from last week's Nashville trip) the innocent, decent man in the picture below is me, trying to perform a very natural bladder evacuation procedure. The roommate who snapped the picture, emailed it to numerous friends and likely posted it on the internet... well, he's a sonofabitch.
I hope I've been helpful in attempting to clarify the true meaning of the term.