He's not a mosquito, he's not a smoldering ember, he's likely not even a mentally ill person. Imprisoning anyone for researching alternative viewpoints (even if you believe to be evil) is wrong and you don't punish people for it. This man did nothing other than basically research and as far as anyone can tell had no plans to do anything further.
In my 20s I downloaded a copy of the big book of mischief. I never tried to make anything from the book, probably good I didn't or I might not be here now, however by the logic that convicted this guy I could have faced years in prison... for curiosity.
No matter which way you cut it this is wrong.