> courts reject arguments like this.

If by "arguments like this," you mean following the law but with suspect motives, then one of the strengths of the legal system in the US is that the courts absolutely accept arguments like these.

In criminal matters, you typically need both intent and some act forbidden by statute before a finding of guilt. You can't indict someone for ill will.

Intent alone is not generally sufficient for a conviction is the US, save for some cases of special liability (attempts, or some forms of aider and abettor or conspiracy). Sometimes intent doesn't matter at all, but that's generally reserved for traffic cases or statutory rape, where intent would pose special difficulties proving beyond a reasonable doubt at trial.

I can think of only a few notable counterexamples where a court made inferences about true intent and made a finding against a party despite a standing rule that would have let them off. MGM v. Grokster could be read that way. Grokster ran a service with "substantial noninfringing uses," which was previously sufficient for a defense of fair use. However, Grokster was found to infringe based on their constant encouragement for people to use their services to infringe. Grokster had "the object of promoting [their service's] use to infringe copyright, as shown by clear expression or other affirmative steps taken to foster infringement." You could read that as a sort of retroactive punishment for ill intentioned behavior.

Here's the twist though, that wasn't criminal law. There's generally a much higher bar for criminal law to strictly apply statutes as written. In civil law, both parties are citizens with equal rights before the courts, so there's more of a balancing test. In criminal law, most presumptions run against the state.

This isn't just a US twist. A German scholar of jurisprudence, Friedrich Carl von Savigny, was one of the first to argue that criminal (and tax) laws must be interpreted as narrowly as possible, because people deserve fair and clear warning of what is allowed and prohibited. See also the "Rule of Lenity" in statutory interpretation, whereby ambiguous criminal statutes are interpreted in favor of the defendant (wikipedia points to McNally v. US and a few other relevant cases):
https://en.wikipedia.org/wiki/Statutory_interpretation#Canon...

This isn't just a convention in the US though, judges cannot extend criminal laws to criminalize novel activity, because that would violate prohibitions against "ex post facto" laws under Art. 1 Sec. 9 of the Constitution. Ie, the Constitution forbids making some act a crime after it happened, the state must provide advanced warning. (Well, technically it's a violation of 14th Amendment Due Process, since Art. 1 Sec. 9 only binds the legislature, but similar principles apply). A fuller treatment can be found on this issue from the Supreme Court in Bouie v. City of Columbia and Rogers v. Tennessee.
https://en.wikipedia.org/wiki/Bouie_v._City_of_Columbia
https://en.wikipedia.org/wiki/Rogers_v._Tennessee

Although dissenting, and again not in criminal law, Scalia provided a nice quip on the subject in the recent Aereo opinion:
"It is the role of good lawyers to identify and exploit [legal loopholes], and the role of Congress to eliminate them if it wishes."
American Broadcasting Cos. v. Aereo, Inc., (Scalia, dissenting)

(To the point of the intent required by the CFAA, which might be in question here, Kalow v. Springnut would probably be illustrative: http://blog.internetcases.com/2008/07/17/cfaa-requires-inten... )