In a report published by the Irish Data Protection Commissioner (DPC), it was revealed that LinkedIn has been using 18 million non-user emails to generate targeted ads on Facebook. It was also shown that LinkedIn has been using the personal data of its users to automatically build professional networks.
https://www.notebookcheck.net/LinkedIn-used-18-million-non-user-emails-to-buy-targeted-ads-on-Facebook.366941.0.html