From CNN

After the attack on the Westgate mall in Nairobi, Kenya, substantial attention was given to the some 40 Americans who have traveled to fight for Al-Shabaab in Somalia during the past several years.

But much less attention has focused on Al-Shabaab’s supporters in the United States who have helped to fund the terrorist group. Those supporters have funneled tens of thousands of dollars via money transfer businesses to the terrorist organization and have often maintained direct contact with Al-Shabaab leaders and fighters in Somalia.

After the 9/11 attacks, when it became clear to investigators that al Qaeda’s deadly assaults on New York and Washington had cost as much as $500,000 to mount, the U.S. government became far more aggressive about trying to block funds going to terrorist organizations.

Part of that process involved a determined effort to sort through which groups were terrorist organizations. On 9/11 there were only 26 terrorist groups on the State Department’s list of designated Foreign Terrorist Organizations. Today there are 51, among them Al-Shabaab, which was designated in March 2008.

The result of that designation was that it was now illegal for a person in the United States to knowingly provide Al-Shabaab with money, training, expertise, false documentation, communications equipment, weapons or explosives, or to join the group.

Read more at cnn.com