Fredric Wertham's It's Still Murder.
This is an article Fredric Wertham wrote after the Comics Code was in place and being enforced. The article appears in April 2nd edition of Saturday Review magazine. He disagrees that the CMAA Code is effectively toning down comics and goes into examples as to why. He also criticizes certain provisions in the code too. Like Seduction of the Innocent, he reprints panels to show why. Click the thumbnails for full sized pages.
Also online is Wertham's 1953 article for Ladies Home Journal titled 'What Parents Don't Know About Comic Books'