[Update] 60% of our users use third party OAuth services (i.e. Google and Facebook) for logging in to Zomato. We don’t have any passwords for these accounts – therefore, these users are at zero risk – both within Zomato, as well as on Google and Facebook (and any other services where the same Google/Facebook ID is being used to log in). For all our other users, as a safety measure, we strongly advise changing your passwords on other services where you might have used the same password as Zomato – we are also sending emails to such users prompting them to do the same as we speak.

http://blog.zomato.com/post/160791675411/security-notice