The concurrence by Judge Gilbert S. Merritt provides a warning:

We should make clear that in the future companies like Lexmark cannot use the DMCA in conjunction with copyright law to create monopolies of manufactured goods for themselves just by tweaking the facts of this case: by, for example, creating a Toner Loading Program that is more complex and ‘creative’ than the one here, or by cutting off other access to the Printer Engine Program. The crucial point is that the DMCA forbids anyone from trafficking in any technology that ‘is primarily designed or produced for the purpose of circumventing a technological measure that effectively controls access to a [protected] work.’ 17 USC �1201(a)(2)(A). The key question is the ‘purpose’ of the circumvention technology. The microchip in SCC’s toner cartridges is intended not to reap any benefit from Toner Loading Program — SCC’s microchip is not designed to measure toner levels — but only for the purpose of making SCC’s competing toner cartridges work with printers manufactured by Lexmark.

By contrast, Lexmark would have us read this statute in such a way that any time a manufacturer intentionally circumvents any technological measure and accesses a protected work it necessarily violates the statute regardless of its ‘purpose.’ Such a reading would ignore the precise language — ‘for the purpose of’ — as well as the main point of the DMCA — to prohibit the pirating of copyright-protected works such as movies, music, and computer programs. If we were to adopt Lexmark’s reading of the statute, manufacturers could potentially create monopolies for replacement parts simply by using similar, but more creative, lock-out codes. Automobile manufacturers, for example, could control the entire market of replacement parts for their vehicles by including lock-out chips. Congress did not intend to allow the DMCA to be used offensively in this manner, but rather only sought to reach those who circumvented protective measures ‘for the purpose’ of pirating works protected by the copyright statute.

Judge Merritt concludes:

On remand the first question should be whether Lexmark can show the requisite ‘primary purpose’ to pirate a copyrighted work rather than to ensure that their own cartridges work with Lexmark’s printer. If not, its case against SCC should be dismissed.