The Twitter users who drove the furor over Komen and Planned Parenthood

Last Tuesday, the Susan G. Komen Foundation announced it would no longer fund clinical breast exams and mammograms through Planned Parenthood. The $680,000 per year that was going to Planned Parenthood helped provide exams for 170,000 mainly low-income and minority women. The organization claimed that they were tightening their rules for grant recipients and denying grants to any organization under investigation. (A pro-life Congressman from Florida is leading a Congressional inquiry into whether Planned Parenthood uses public money to fund abortions--an initiative many see as politically motivated.)

On Friday, February 3 the organization abruptly reversed its decision amid a firestorm of criticism on Twitter, Facebook, and many blogs.There is little doubt that social and media pressure forced Komen to reverse its plan. The Figure shows the representative Twitter hashtags associated with Komen during the controversy, from January 31-February 3.

Sorting through over 100,000 tweets that were sent in regard to Komen during the controversy, we see that they are dominated by critics of the move. Just three of the top 28 hashtags support Komen's move (1 is ambiguous).

In order to examine what drove this message, we took a look at a new tool called "influencers" created by the Yahoo! Labs Content Science team, which we are going to use extensively on The Signal. Influencers are the Twitter users who help spread a message. They tweet a lot on a particular topic, are retweeted, and have a big following.

The influencers in this controversy are a combination of official organization Twitter accounts, journalists, and some unaffiliated tweeters. There was both a top element to the distribution of this message, but also a broad-based push, especially in last two days. Pro-life groups never got much traction, with just one influencer on the list:

We can see that the pro-choice groups mobilized well, and we can see that their comments were clustered around pro-choice slogans. Here are representative retweeted tweets relating to the controversy by day:

January 31: RT @ppact: ALERT: Susan G. Komen caves under anti-choice pressure, ends funding for breast cancer screenings @ PP http://t.co/T17wWxHM

February 1: RT @MishaRN: Donate to Planned Parenthood & request a thank you card be sent to: Karen Handel c/o Susan G. Komen Foundation

February 2: RT @AdamSerwer: Will Komen cancel its $7.5 million grant to Penn State, which like PP is under federal investigation? http://t.co/Y96Yw3RX

February 3: RT @WayneSlater: Stunning reversal. Nancy Brinker/Komen for Cure backs down. Will continue to fund Planned Parenthood. http://t.co/zji3TCuU

Like most online campaigns, this one was a combination of established, influential voices and a more genuinely viral group of commentators. Expect to see a lot more from our influencers tool in the future.

David Rothschild is an economist at Yahoo! Research. He has a Ph.D. in applied economics from the Wharton School of Business at the University of Pennsylvania. His dissertation is in creating aggregated forecasts from individual-level information. Follow him on Twitter @DavMicRot and email him at thesignal@yahoo-inc.com. The content science team at Yahoo! Labs contributed the data for this analysis.

Correction, 6:02 p.m. ET: This article has been updated to reflect that the Yahoo content science team, and not any particular individuals, developed the tools used to collect the "influencers" data. The error was made during editing.

Other popular Yahoo! News stories:
• Yes, Washington is in fact more partisan now
• Gingrich doubles-down on Romney in final Nevada swing
• Obama touts new jobs numbers, warns Congress not to 'muck up' recovery

Want more? Visit The Signal blog or connect with us on Facebook and follow us on Twitter.