Check your sources. is the author marked as contributor? -> find their twitter account and check the background. Most sites have open editorial, or blogs, or contributor's section. More sites will have open editorial sections as the journos are laid off each day. And again check the source.

It's not a great fix, though, because less-blatant PR groups just send out draft stories or note lists which can be easily converted into news stories. So even professional, non-bribed journalists who need a quick piece will often end up writing the obvious story based on someone else's script.