Certainly some people have. A court case recently had Amazon turn over Echo recordings.
Similarly, your DNA could be used to place you in relation to a crime scene whether you committed that crime or not. I certainly don't want someone I bumped into earlier to have my DNA on them when their body is found if my DNA is trivially searchable. I'd much rather have them need to go through me and my lawyer before any of that is possible.
I don't like the better-safe-than-sorry argument when it comes to security. I think it leads to bad policy and bad decisions. I've been thinking about this after I read a story[1] about a family that has been told that they cannot let their young kids ride a city bus by themselves. It's a similar argument - the value of kids gaining independence is big and the risk of something atrocious happening is tiny.
[1]:https://www.thestar.com/news/canada/2017/09/06/a-dad-in-bc-l...
Depends on your lifestyle and how valuable you think these things are, but I find these things almost entirely valueless. I think virtual assistants are basically total trash - I can type my query on my damn phone faster and more accurately than the Echo or Google can get it - and I just see no value in DNA sequencing unless you're looking for a specific medical condition, the fluffy interest in stuff like racial makeup just seems like a shitty trade-off to me.
Also keep in mind that with DNA you are not just making the decision for yourself. Your relatives share significant parts of your DNA, thus the potential risks will affect your brothers kids /etc as well. Consider asking their opinion / getting their consent.
I'm willing to tolerate a pretty high level of risk. I either drive my car or ride my bicycle to work 5 days a week. I've gone scuba diving before. I rode a motorcycle for 30 years (I just sold it). I occasionally eat fast food. Crazy, right?
For 23andMe, do you know of some ways that people have actually been harmed by their test results? I wonder what percentage of their customers regret signing up?
I doubt most of the people intentionally avoiding Alexas and 23andMe also have shower pads that help prevent slipping. This is why I think most of this anxiety comes down to some combination of neo- & techno-phobia, like we saw with GMO crops.