In Christiana there is a street called 'pusher street'. It a place where people use and sell soft drugs. The pushers are not so happy if you take a picture here. "I'll smash your camera", was the start of the first conversation I had in Danmark. Later I discovered on one of my photo's a sign that taking photo's was not allowed.
Christiana is well worth a visit, though perhaps not so much if you are a voyeur type of tourist. The community is pretty off-beat and generally laid-back and sitting having a beer and passing the time of day (or whatever) with the locals made for a pleasant afternoon.
One thing they are not laid-back about however is photographs. I had no sooner taken this one when a guy on a push bike screeched up to me and demanded, in no uncertain terms, that I delete it. He relented a bit when I explained that the reason that I took it was for the purpose of writing a short piece on the internet about not taking photographs here, and then having been shown that the photo was quite literally just the "No Foto" sign he let it go at that - so you have been warned!!
BTW beer is pretty cheap here ;)
Despite being a great cooperative community, government repression of Christiania has led to a "thug" element of drug dealers here- I was threatened by one here (just minding my own business). I was told marijuana used to be sold here openly like in Amsterdam, but now that is not permitted, and it's the lowlifes that are left selling the stuff. Dosen't seem to be a threat of muggings here, however, and aside from avoiding the dealers, there is no reason not to see this aspect of Danish culture.