https://blog.quora.com/Quora-Security-Update seems to be misleading, especially the introduction. They start with 'some user data was compromised', however, it seems that for 'approximately 100 million Quora users' – that's basically all users! – all user data was compromised …

In addition, many questions remain open, for example: Which ' leading digital forensics and security firm' is working for Quora?

I hope for Quora that they met their 72-hour deadline according to the GDPR. Looking at https://www.quora.com/about/privacy, it does not look if Quora was / is GDPR-ready. They do not mention any legal basis for the processing (art. 13 GDPR) and they do not inform about their GDPR data representative in the EU (art. 27 GDPR).