John, first of all I didn't email your entire staff only the people who I thought would respond to my concerns. I never expected to receive an email from David directly. Secondly, It wasn't hard to 'track down every Tumblr employees email' your email addresses are quite easy to figure out, take yours for example 'john@tumblr.com' and your employees are featured on your about page.
I would also like to point out that after I sent the email I tried to have a discussion with David directly but unfortunately he ignored my emails.