I don't know about the RIAA and mixtapes, but the MPAA tried to get VCRs banned. As Jack Valenti (MPAA) explained to a congressional panel, "I say to you that the VCR is to the American film producer and the American public as the Boston strangler is to the woman home alone."

Just wait until Disney finds out that you can make Mickey Mouse shaped pieces of plastic on an Ultimaker.

I expect part of the reason is that the genie was already so far out of the bottle with cassette tape (and even reel-to-reel) that even they probably felt that it was pointless at that point to fight. However, a number of countries did impose a fee on blank media: http://en.wikipedia.org/wiki/Private_copying_levy

Au contraire: https://en.wikipedia.org/wiki/Home_Taping_Is_Killing_Music

New sensors coming down the pipeline will allow your smartphone camera to image objects down to micron resolutions from ~1 meter away.

http://www.pcworld.com/article/2906232/camera-chip-could-tur...

Consider everyday things around you: smartphones, laptops, etc. None of these can be 3dprinted. Things you can 3d print are... smartphone cover, smartphone stand... things you can afford to be plastic in its entirety. I think you guys are overestimating what 3dprinters are capable of. There's a lot of tinkering required to create anything of even moderate complication. And it's almost always cheaper to just buy it if it's available at the store, because the printer costs and the consumables (pla, abs or whatever filament) costs, and time costs.