Before I start off with this blog post, I just want to greet everyone a happy and prosperous new year!
Moving on…

Is it just me, or you guys also get curious about your unfollower on Tumblr? I used to think that there will be no way for me to know who unfollows me, but thanks to this guy right here, Lewis Theobald -- a technology wizz who runs his own design company called OpenInferno, we can know find out who unfollowed us! OpenInferno Webmaster
Lewis made a website where we can track our unfollowers. He called it “TumblrStalk”. TumblrStalk uses Data Scraping methods using a free open-source PHP script, SecureCrawler. Through this, the script takes your username & password loads the Tumblr page in a backend request, if your details are valid then you are remotely logged in, during which the script will scan through your follower pages and record the results.
On a related note, you can also know your unfollowers by using the Missing E extension.