[A1kmm]

IANAL, but it is not a general prohibition on circumventing "access controls", so he may not need to rely on an exception.

17USCs1201 (added by the DMCA) says: (a) Violations Regarding Circumvention of Technological Measures. - (1)(A) No person shall circumvent a technological measure that effectively controls access to a work protected under this title. The prohibition contained in the preceding sentence shall take effect at the end of the 2-year period beginning on the date of the enactment of this chapter.

So the technological measure must "effectively control access to a [Copyrighted work]".

Jailbreaking a games console does not circumvent the technical measures that prevent copying - at most, it might circumvent technical measures that prevent someone from circumventing technical measures.

The Court of Appeals for the 9th Circuit (including California) has a precedent that makes the anti-circumvention provision rather broad (more than a plain language interpretation of the law would otherwise imply); other circuit court rulings have interpreted the law to be much more narrow and not cover circumvention that doesn't allow / involve copying; presumably this is why Sony wants it heard in California and Geohot wants it heard in New Jersey (under the jurisdiction of the Court of Appeals for the 3rd Circuit).