Seth Finkelstein writes "The Copyright Office recently
announced the current three years
Digital Millennium Copyright
for "classes of works subject subject to the exemption from the
prohibit on against circumvention of technological measures that
control access to copyrighted works".
Very roughly, the exemptions are:
2) Obsolete computer programs restricted by broken "dongles"
3) Computer programs and video games from obsolete hardware
4) E-books where all versions can't be used by the blind
Full details are in
Recommendation of the Register of Copyrights
As a note of personal credit, "The Register's recommendation in favor
of this [censorware] exemption is based primarily on the evidence
introduced in the comments and
by one person,
a non-lawyer participating on his own behalf.""