A dream team of computer+law geeks have put together an appelant brief in Weev's defense. A major feature is that simply "unwanted" access doesn't mean "unauthorized" under the law: just because you don't like what I do doesn't necessarily make me a criminal.
For example, I use "AdBlock" to block advertisements from websites. Since websites earn money from advertisements, my free-riding with AdBlock is unwanted access. But is this conduct prohibited under the CFAA? I don't think so, but then, I wouldn't have thought Weev's (adding one to a URL) or Lori Drew's (violating ToS) conduct illegal either.
In the following two screenshots I demonstrate what AdBlock does. The first shows my access without ads on the site "Volokh.com". Notice the 'stop sign" icon near the URL which indicates how many items on the page have been blocked. Also notice my smiling face in the "comments" section -- I included that in the screen capture so that you know it's me, so that if "Volokh.com" chooses to prosecute me for this, the evidence of my guilt is clear. The second screenshot shows what the site looks like with AdBlock disabled.