I'm pretty sure looking at it isn't the illegal part. Making, possessing, and distributing are the illegal bits. Maybe some other aspects too, like transporting or buying or some form of conspiring? I don't think the government (at least the US gov't) can actually make looking at anything illegal. But it's hard to look at something that's restricted in that way without doing at least one of the illegal things.

If just looking were illegal, you could shove it in someone's face on the sidewalk and they'd instantly be guilty of a serious crime.