http://en.wikipedia.org/wiki/Reasonable_person
You can't parse sentences out of context and apply programmer logic to them, that's not how laws work.
It's true that Judge Kozinski in the 9th Circuit said he would not "apply a badly drafted piece of legislation to lead to [an] absurd result."
But the issue is not cut and dry.
Kozinski essentially acknowledged he was interpreting the statute in a manner possibly at odds with its very language. These courts get reversed all the time (over 70% of their cases) - and other circuits have read the law more narrowly.
And the government itself supports a narrow reading of the law.
OP's article is over the top. My point is, the "authorization" part of the law appears extremely broad and as the DOJ puts it: "the case law on this issue is muddy."
As for common law:
http://en.wikipedia.org/wiki/Common_law
I am still not a lawyer.
Common law is judge-made and only governs in the absence of statutory authority. (Due process and trial by jury are constitutional laws). The reasonable man is primarily a negligence standard.
http://online.wsj.com/article/SB1000142405311190406060457657...