Tom Foremski has an article about bloggers falling prey to standard public relations techniques.

It is impossible to work as a professional journalist and not be influenced in some way. If this wasn’t true, there would not be a massive public relations industry

Agreed, everyone is biased in some way. Some are less biased than others. If you say you are not biased, you are lying. It's sort of like, the only crazy people are the ones who claim they are not crazy.

I believe that some bloggers are in danger of losing their independence and their unique voice within the media landscape—if they become pulled into a sphere of influence. This is the “sphere” that professional journalists operate in every day and cannot avoid.

He promises more to come in this thread.

A few years ago I was on the other side of the fence. I was not in a PR position, but the president of a local tech company. The local paper had a tech reporter who was not that technical. This reporter would often call me and ask about various tech issues or for story ideas. I would often steer him towards clients that used certain technologies or give him leads on other stories. This resulted in me being quoted numerous times in articles, or my company being mentioned as 'working' with the subject of the story. So how biased was the coverage? An article was never written with my company as the feature, but we did get a great deal of ink.