When the law was extended...in 1996, a Senate report said its goal was to "increase protection for the privacy and confidentiality of computer information." As a result, the 9th Circuit reasons "the prohibition on unauthorized access is properly understood to apply only to private information - information delineated as private through use of a permission requirement of some sort."
-- Timothy B. Lee, Ars Technica
That makes sense, to me. I mean, in the physical world, hiQ (the data company scraping LinkedIn public profiles) could count or photograph cars going in and out of the Microsoft parking lots, or digitize local phone books (which were created using publicly-available data). The interwebs are a big, mostly public, place. I always raise an eyebrow when people with Facebook accounts rail against Facebook over privacy.