Bloggers don't want to be plagiarised because the plagiarism destroys the remuneration that they get from their work: reputation, feedback, etc. Pay for media doesn't want to have work copied because it deprives them of their form of remuneration: money.

They're both exercising control over an intellectual property so that they get something back from it. I see that there might be mild differences (for example, copying still provides some possibility of the owner getting something back, since the authorship link is retained), but fundamentally, it's the same right that is getting exercised.