The author probably meant 1st Amendment, but Zimmerman and the EFF also relied on 5th Amendment arguments. See, e.g., https://readingroom.law.gsu.edu/gsulr/vol1

The author probably meant 1st Amendment, but Zimmerman and the EFF also relied on 5th Amendment arguments. See, e.g., https://readingroom.law.gsu.edu/gsulr/vol13/iss2/14/ https://readingroom.law.gsu.edu/gsulr/vol13/iss2/14/. While the 1995 press release from the EFF (https://www.eff.org/press/archives/2008/04/21-42 https://www.eff.org/press/archives/2008/04/21-42) specifically mentions only the First Amendment directly, if you look at the list of arguments under "More specifically, the current export control process:", about half of them are Fifth Amendment or Fifth Amendment-adjacent defenses.