Pamela Geller organized the “Draw Muhammad” contest and art exhibition held Sunday in Garland, Texas, where two gunmen opened fire before being killed by police. Geller also placed an order for subway and bus ads in New York City that linked Islamic leaders to Hitler, leading the New York Metropolitan Transportation Authority to vote Wednesday for a blanket ban on “viewpoint advertising” to avoid ever having to show ads like Geller’s again.

It’s not a quirk of timing that places Geller at the heart of two controversies over provocative speech about Islam within a week. The little data we have shows that although anti-Islam groups have multiplied in the United States over the past several years, only a small group of people are behind many of these organizations. Geller is one of them.

The Southern Poverty Law Center (SPLC) began identifying anti-Muslim “hate groups” in 2010 after controversy flared over the proposed Cordoba House mosque, a few blocks from the World Trade Center site. In 2010, there were five active anti-Muslim hate groups — organizations that, by the SPLC’s criteria, “exhibit extreme hostility toward Muslims” and “broadly defame Islam, which they tend to treat as a monolithic and evil religion.” (A group does not need to advocate violence explicitly to be included on the SPLC list.)

The SPLC’s tally ballooned to 30 in 2011 and then 36 in 2012 and 2013. The SPLC’s Spring 2015 Intelligence Report’s count of 24 represents the first decline in anti-Muslim hate groups since the SPLC began its watch, and was part of an overall decline in labeled hate groups from 939 in 2013 to 784 in 2014. (Of course, the number of groups and the number of supporters of those groups are two different things. Information on membership is frequently not available.)

But the simple count of anti-Islam groups can be deceptive. Growth in anti-Muslim groups seems to be driven as much by a few key leaders founding multiple organizations as by new people forming independent groups.

When Geller held her “Draw Muhammed” event, she did so under the aegis of the American Freedom Defense Initiative, of which she is the executive director. The ads that Geller ordered in New York mention the American Freedom Defense Initiative in their disclaimers but direct readers to Jihad Watch, Atlas Shrugs and Truth About Quran.

The American Freedom Defense Initiative, Jihad Watch and Atlas Shrugs are listed by SPLC as hate groups. Atlas Shrugs’s website simply redirects to Geller’s personal website, and according to tax filings, Geller is also president of Jihad Watch. Robert Spencer, the writer who runs Jihad Watch, also co-founded Stop Islamization of America (SIOA) with Geller. The website of SIOA, which is also on the hate-group list, redirects to a subsite of the American Freedom Defense Initiative.

In other words, Geller and Spencer are, between the two of them, the leaders of 17 percent (four of 24) of all the anti-Muslim groups that the SPLC tracks. Mark Potok, a senior fellow at the SPLC, explained that his organization lists each group separately because the groups may engage in different patterns of activity.

A 2014 report by the Council on American-Islamic Relations (CAIR) found a similar pattern of centralization among anti-Islam organizations. CAIR listed 37 active groups in the “inner core” of what it considers Islamophobia activism and 32 additional groups in an “outer core.” Inner-core organizations tend to be focused particularly on Islam; outer-core groups provide financial or other supports to the inner core but may work on a wider array of issues. Board membership and funding sources frequently overlapped between nominally separate groups.

A Center for American Progress (CAP) report in 2011 — titled “Fear, Inc.” — had similar findings. It identified seven top funders of anti-Islamic research and rhetoric. These groups contributed $42.6 million to “Islamophobia think tanks” between 2001 and 2009. All of these funders gave to at least three of the eight Islamophobic groups that CAP tracked.

All that money buys the appearance of a growing movement, but although Geller and a few others will continue to hold events and issue challenges, the most prominent anti-Muslim hate groups remain the product of a small group of leaders acting under many different names and logos.