Over a year ago, Yahoo purchased the blog host Tumblr for $1.1 billion. Today their investment is not looking so good. Rather than seeing growth, in the past six months Tumblr had lost over 7 million users.

Back in December, Tumblr boasted 49 million regular users. As of yesterday, consumer reports showed only 42 million. That's a 15 percent drop in traffic, presenting a problem for Yahoo, which has been trying to attract advertisers for the blogging service in order to monetize it.

When Yahoo first made the purchase, they stated that they would not make changes, and true to their word, Tumblr has remained more or less the same as it has been for years. No overhead policy change can really explain the loss of users (and consequently revenue.)

What has changed on Tumblr is the user base. Or perhaps it would be more accurate to say that the perception of Tumblr's user base has changed. See, when I hear the word 'Tumblr' my mind immediately jumps to one demographic: 14-24 year old social justice bloggers. It's not fair. They are not the only group on Tumblr. Frankly, they are a minority. They are just the loudest.

As a group they are fairly recent, starting in 2009 and they exert a considerable amount of influence on Tumblr's identity. What started as a trickle in '09 reached an all out crescendo by 2012 and became some of the loudest voices on Tumblr. But until now you might not have heard of them.

That's what's changed. Over the past year many of Tumblr's fringe causes and controversial methods have caught the attention of national media outlets, looking to both ridicule them or monetize off of them. The social justice movements ideologies of class and privilege, once reserved for academic papers and message board discussions began to get attention in big name publications. Mother Jones, Salon, Reason and National Review have all started shining their probe-lights into this dark little corner of the internet.

And they found that the causes have become even more radical. Back in 2009 the social justice blogosphere kept to more mainstream causes. This was when same-sex marriage was at the fore of national attention and California's infamous Proposition 8 was all the buzz. This went into 2011 when Occupy Wall Street was a thing and income inequality was the big issue. Then things started to get a little... weird.

Look at any social justice hashtag on tumblr today and you will discover some things that you might want to forget (for that I recommend the excellent Eye Bleach subreddit). You will be told to “check your privilege,” an ill defined statement that seems to mean “feel guilty for the sins of your neighbor's ancestors.” Then you might find the “Fat Acceptance” movement. Then there are "otherkin", people claiming to be animals trapped in people's bodies and claiming they are institutionally oppressed because of that. There is a Tumblr dedicated to explaining how men sitting down on public transportation is a tool of "systemic violence." The list goes on and on.

Then there were the questionable methods these groups used to make their message. Rants, manifestos, death threats and doxxing- or ferreting out an anonymous user's real world information and outing them for everybody to see- became so common in these communities that other users made Tumblr accounts just to showcase the worst examples.

And this is what the national papers covered. This was the face that Tumblr ultimately showed the world- a face made of fringe groups with bizarre causes. And If I were a casual Tumblr user who just wanted to post about the newest iPhone or a cool video game or blog about wage policy (yes, I did that, I can be pretty dull at times), I sure would not want to put up with that sort of baggage representing my blog.

I know a fair amount of former Tumblr users. They all say this movement it what pushed them away from the site. Heck, it's why I left. It might not be enough to account for all seven million lost users, but it is significant.

It's a toxic environment, and people want out.