The capabilities of technology are not what frightens me.
What frightens me are the motivations and ethics of developers and engineers. The aspiration of entrepreneurs. The ethics of society as technologies evolve. The majority level of intelligence of those societies harnessing advanced technologies, and the accessibility restrictions of less privileged members of those societies to not only utilization but control of those technologies.
At the end of the day, this is still cool. However, the terrifying parts are in line with Orwell's 1984, which we arrived at circa 2007.