Glenn Reynolds discusses the motives of CBS in attacking Atrios. Meanwhile, Henry Copeland at Blogads' blog posts several different iterations of the CBS article.
Personally, I don't believe bloggers should be legally obliged to disclose the fact that they're on the political payroll. The market can sort them out if there's any reason - God knows the blogosphere is capable of doing a little digging to find the truth.
I apologise for being so blunt and not bothering with a reasoned argument to make CBS understand that the First Amendment works for us, too, but I only have one thing to say:-
Kiss my shiny metal ass.