Daniel MacArthur: "Sample swaps at 23andMe: a cautionary tale".
It appears that a single 96-well plate of customer DNA was affected by the mix-up. This resulted in incorrect results being sent to customers, with some alarming consequences; one mother posted on the 23andMe community about her distress upon discovering that her son's results were incompatible with the rest of the family:
Not a happy story of genetic discovery, but in the end her son is in fact her own. You hear about genetic information making people question their identity -- this is the depth of impact genetic testing can have.
It's also amazing to me that there are already families submitting swabs for both parents and children. Talk about disposable income!