23ANDME

The central fact of the 2023 23andMe incident is not that some customers reused passwords. It is that one successful login could reveal information about many genetic relatives who did not reuse that password, did not control the accessed account and could not see the session that exposed them. That shared-profile structure changes the accountability test: authentication defaults, relationship visibility, scraping controls, notification boundaries and cross-border data governance all have to be judged against the reach of an account, not merely the number of accounts taken over.