Since people are retarded enough to arrest someone and call hentai manga child pornography seems its happened occasionally from what I can gather spending 1 minute googling. I knew something like this had of happened before just didn't remember if it was for hentai or actual real porn.
I think they just pick people because of how they look or someone thinks their really weird and decide "hey let's put this guy in jail and blame it on smut he has on his harddrive since no one likes him anyway"
This has to be the dumbest thing anyone has ever been arrested for as long as they aren't prawling the streets for little boys/girls or trying to hook up with them on the internet I dont see the harm.