There are always potentially dangerous extrapolations with any discovery or invention we make. I think we are better off focusing on the possible advantages of refined brain-to-brain interface technology - like the development of neural prosthetics and biomechatronics that will put a smile on people who have been impaired by all sorts of traumas. Think about how this new technology will help the Walk Again Project in the future.
We can't allow our fears of new and revolutionary technology getting into the wrong hands. If we did this we'd be hopeless to those who could do with technological help. There will always be those who will want to get their hands on fantastic boons to further their power. Everyone craves expansion. But I don't think we'll turn into "Borgs".
A religious mentality dominates a great portion of the world of politics even today. We live in a world where, unfortunately, many politicians still think a bishop or a Pope is better qualified than a scientist in making the decision of whether or not embryos should be destroyed for the sake of advancing stem cell research.
Politicians also like to listen to the majority's opinions while minorities are largely ignored. Sure, many will try to give people a run for their money in the seat of power, but they also like to keep a sense of democracy alive and this technological business will provide them with a brilliant opportunity. They care about the votes. You will never get an atheistic scientist for a president unless he is lying about his beliefs, but you will get a religious one because the majority are religious, and, if the majority see sense in advocating the use of this technology in the medical field, then so it is - the public, in the minds of those in power, have already decided on the best course of action for such a politically trivial
matter. The government will only be helping the people to help themselves and everyone will prosper. Meanwhile, there is no plebeian authority in declaring war against other countries, for example.
They provide an image and they have to let people know that they are mostly listening to their opinions. They will happily make this available for the sake of attending to people's needs and not so much their ambitions. Ambitions are for governments and their intelligence centres are up to par with everything. They won't hesitate to use this technology in warfare if possible but I'd imagine extra measures to control its availability would be taken.
Nobody wants to be controlled or have their privacy invaded. Most of the religions in the world would abhor the extrapolation you proposed. It would never be sanctioned in those terms. If it will one day, then we are light-years from it. Then again, the Borg scenario could even improve mankind and make us more understanding of others. Imagine if we could fix
'psychological defects' with this technology! What if this helps us to reach a global consensus on all matters, including ethics, if we truly acquire a broad perspective on the human mind and the plethora of its flavours.
Of course, there is the fear that we will all be turned into marionettes. But what makes us think that we are in control now? Most people think we have free will, but, if you think about it, we only behave according to the environment, our genomes, events in the course of our lives, and how we feel. None of which we pick - not to mention the profundity of the unpredictability of future thoughts. We are nature's puppets even today. A change of scenery could even be good for us even if it will never be our ideal utopia. As someone once said, a puppet feels free as long as he loves his strings. For more on free will:viewtopic.php?f=1&t=1061