Thirty years after the invention of the printing press, one of the most popular printed books was the Malleus Maleficarum, a treatise on witchcraft which triggered a witch-hunting hysteria that lasted centuries. The corrosive effect of disinformation has been clear for centuries and the medium by which it is disseminated is, in my opinion, hardly the concern. My concern is that until very recently, the controllers of these mediums (e.g. Facebook, Twitter) insisted that all ideas deserve a level playing field, rather than accept that some ideas are simply better than others.
> Before the 19th century, invention and innovation emerged primarily from craft traditions among people who were not scientists and who were typically unaware of pertinent scientific developments.
I think for every pre-19th century innovation that occurred in an "information bubble" there were many more that depended on the Renaissance attitudes toward science and discovery that were themselves predicated on earlier discoveries. If I had to give a realistic estimate as to when innovation truly happened without knowledge of pertinent scientific developments, I would look back to pre-Galilean times.