That thing is clearly not a thought, but a literal lethal weapon. You know what would actually be dystopian? Gun violence happening on a regular basis.
Of course, the headline just says it was 'seized'. That could happen for an airsoft gun in Japan for all I know.
Given the circumstances and confession I’m guessing this guy will be let off with a warning (deferred prosecution).
Don’t fall into the “scary weapon!” trope. Thankfully I live in America where most people don’t freak out like this and we can have cool hobby projects.
Just ask yourself-- how many people are killed by coil guns each year? Stopping their proliferation strikes me as utterly useless regulatory overreach that benefits exactly no one, and deprives many a nerd of a cool hobby project.