MAI Systems v. Peak Computer[0] says otherwise, at least in the 9th Circuit and at least covering use of the program. Other courts and Congress have bent over backwards to try and not disturb the ruling.
Even if it was overturned, modification has been a core part of copyright law since Folsom v. Marsh[1], where the Supreme Court interpreted the entire concept of derivative rights into the law. In fact, this ruling was so expansive they had to invent fair use at the same time just to avoid accidentally overturning the 1st Amendment.
Copyright creates the restriction, specifically to legally mandate a negotiation for the license that absolves you of the restriction. If you do not have a license, you have nothing but a pending lawsuit.
This case establishes that the copy in question was in fact a "copy" as defined by the copyright act, but the infringement was due to the disposition of the parties' rights via a license - not inherent to the copyright. This ruling is highly specific to the case.
Even if it was overturned, modification has been a core part of copyright law since Folsom v. Marsh[1], where the Supreme Court interpreted the entire concept of derivative rights into the law. In fact, this ruling was so expansive they had to invent fair use at the same time just to avoid accidentally overturning the 1st Amendment.
Copyright creates the restriction, specifically to legally mandate a negotiation for the license that absolves you of the restriction. If you do not have a license, you have nothing but a pending lawsuit.
[0] https://en.wikipedia.org/wiki/MAI_Systems_Corp._v._Peak_Comp....
[1] https://en.wikipedia.org/wiki/Folsom_v._Marsh