A blog post can be used in its entirety as evidence without violating the author's copyright. That's the ruling of the United States District Court in Northern Illinois in the case of Denison v. Larkin.
The case came up in an unusual fashion. Denison, an Illinois attorney, was charged with a disciplinary offense for scathing posts accusing the Cook County Illinois Probate Court and its guardian ad litem of corruption, elder abuse, and taking action that physically and emotionally harmed her 90-year-old Mary Sykes.
Denison was charged with violating the Code of Professional Conduct by her accusations. Setting aside the First Amendment issue (which is substantial), Denison challenged the action by suing her accusers in federal court for violating her copyright by utilizing the entirety of her blog post in the disciplinary complaint.
Judge Amy J. St. Eve of the Northern District of Illinois had no problem finding for the defendants and dismissing Denison's complaint. The Court discussed the touchstones for determining whether something falls within fair use: The purpose and character of the use; the nature of the work; the amount of the work used; and the market effect. The court found that under the facts of the case, each of these factors favored the defendants.
Perhaps more importantly, the court noted that in enacting the Copyright law, the House Judiciary Committee stated that "reproduction of a work in legislative or judicial proceedings or reports" is fair use. Further, the U.S. Seventh Circuit (the circuit in which Illinois is located) has held that "reproducing copyrighted works for litigation is an example of the fair use doctrine."
So when you write that blog, remember that it could someday be labeled Exhibit A.