brother-in-law was signed up and he got a message saying his niece was on the service. He doesn't have any nieces. They chatted and he figured it must have been his brother and it was. Pretty crazy.
If this is in fact the story, doesn't this seem like an invasion of privacy on the part of 23andMe?
You have to opt in for the "Relative Finder"
>In rare cases, participation in DNA Relatives may reveal that you are related to someone whom you didn’t expect, or that you are not related to someone in the way that you expected. Consider this before you opt in to this feature.