Genetic testing isn’t the exclusive realm of 23andme, you can get it done through a medical provider as well who doesn’t have such privacy-violating terms.
Right now, yes. But early in 23andMe's history (I got it done at the very beginning) they were pretty much the only game in town. They were the first to make such a service widely accessible to the public, and they helped establish the market in which better alternatives would eventually emerge.
I don't tell anyone now to use 23andMe specifically, but the warnings and risks being discussed here apply to existing customers, to people who have already done it, and I am just speaking as one of those people.
If you're talking about finding specific biological ancestors (names) then yes.
But certain general ancestral data can be deduced from variations in your DNA that are observed in some known current/historical population. I.e, I share much in common with people sampled from Scotland -> I must be Scottish.
People are warned not to put much trust into the ethnicity estimates, sometimes even by the services themselves. Telling western Europeans apart is hard.
It's either matching to specific people in the service's reference group who have declared that they are Scottish, or it's trying to guess based on the mix of ancestral populations 2000+ years ago ("western hunter gatherer", "early Neolithic farmer" etc.)
Maybe for those in the US, or at least parts of it. If there's an option for the other 8 billion people that's at least as good as 23andme from a medical perspective, I think a lot of people on HN would be very interested to learn about it.
