There are the obvious trivial crimes - but what crimes do people think are very much harmless, whilst at the same time being counted as serious crimes?
* In the UK, photoshopping your adult girlfriend to look like she's under 18 (e.g., reduce breast size a bit and paste a school uniform on).
* Come to that, a naughty private picture of your 17 year old girlfriend (particularly interesting in the UK, where the age of consent is 16, but this would still be illegal).
Harmless or not? Both would be one of the most taboo crimes, namely, possession (and indeed, production of) child porn.