find someone's Wordpress knowing his/her email
I'm wondering if it's possible to find out the name of someone's Wordpress account knowing his/her email address (I mean the email he/she has registered the Wordpress account with).
Sometimes they put the email address somewhere in the account so in this case Google can help but if they don't mention the email anywhere in the posts (in the Wordpress blog) and they don't tell you the name of their Wordpress, you need to find another way to figure it out.
So I appreciate any help or suggestion.
Thank you so much