We're really getting into the realm of fantastical scenarios now. The idea that the Chinese government would kidnap the family of a US-based employee in order to force them to hand over data is completely hypothetical, and to my knowledge not backed up by any known case. If they're willing to go to those lengths, they could just as easily blackmail or bribe any random employee. They surely have the power to do so, as does every government with any intelligence service to speak of.
What I do know is that there's an increasing atmosphere of generalized suspicion against Chinese people in the United States, and even of people of Chinese descent. There are lots of recent examples, but to give you just one chilling one: US government pressured Emory University to fire two US-citizen medical researchers of Chinese origin, for the non-crime of pursuing research collaborations in China. The two are leading researchers into Huntington's disease. At the time they pursued their collaborations in China, such collaborations were encouraged by the university, and they pursued them openly. Their entire lab was closed down, and the more junior researchers from China were sent home. This is not an isolated case.
I can't see what's changed to warrant this crackdown in the last few years, other than the quite open discussion in US foreign policy circles about the need to maintain US hegemony, and the long-term threat to that hegemony from a rising China. This has been accompanied in recent months by increasingly hysterical media coverage. One of the most consistently frustrating things about the US is the susceptibility of the public to these periodic campaigns of demonization. Obama laughed about Russia in 2012, but in 2016, Americans suddenly discovered that Russia is the root of all evil in the world - they're even responsible for racial tension in the US! Something similar is happening with China now, and it's reached such proportions that even a Chinese app that teenagers use to share lip-sync videos is a national security risk.