If you still use Facebook (or still has an account) it might be an useful tool to check if you have been involved in the data breach. The tool has been created by Reddit user u/FumazDev, with all the code available on GitHub (frontend and backend), if you want to check for yourself.
Also, here´s the original thread if anyone wants to ask him anything directly.
It´s better to warn them about it. Luckily neither me or my family have been affected by it, but it´s a good tool that more people ought to know about, so I decided to share it here.