It used to (say pre-1800) take a lot of energy to speak to and see someone live from New York to London. Technology unimagined then allows that to happen with orders of magnitude less energy. Who knows what might come along? (I personally don't think there are alien visitors, but I can't say it's impossible)

On the topic of drugs, I agree with Phil but just want to add that a lot of the violent crime around involves drug dealers... almost all the murders in Vancouver (and I'm sure most large and many small cities) are drug related. Make it legal and most of them would go the way of the moonshine runners from prohibition days. (though even that had some benefits, at least to some people - NASCAR wouldn't likely be around without prohibition moonshiners)