A potential al Qaeda plot targeting Belgium was thwarted in part by e-mail information provided by U.S. Internet providers, according to Belgian court documents and Western counterterrorism officials.
The case, which came to light in 2008, shows how U.S. intelligence capabilities can aid in disrupting plots.
On Tuesday, American counterterrorism officials revealed that more than 50 plots have been thwarted since September 11, 2001, using National Security Agency surveillance programs. Many of those plots were overseas.
The officials, testifying before the House Intelligence Committee, revealed only four of those plots and promised to provide details on the others to Congress in a classified setting. The Belgium plot, though not confirmed to be one of the 50 that relied on the recently revealed secretive NSA program to monitor online messages, appears to fit the bill.
On December 11, 2008, Belgian authorities arrested an al Qaeda cell in Brussels that they feared had been planning a suicide bombing attack.
An intercepted e-mail from one of the cell members to his ex-girlfriend indicated he was about to launch a suicide attack. A defense lawyer in the case told CNN that prosecutors at trial acknowledged that the United States intercepted the communication and passed it to the Belgians.
In addition, a Western counterterrorism official told CNN that an intelligence agency from a partner country had intercepted another communication from the cell, that further suggested they may be about to launch an attack and passed the information onto the Belgians. Court documents in the case suggest this intercept was also made by U.S. intelligence.
The cell had been recruited in late 2007 to travel to Pakistan by Malika El Aroud and Moez Garsallaoui, a husband-and-wife team championing al Qaeda's cause in Europe.
El Aroud and Garsallaoui had been on the radar of Belgian authorities for many years. El Aroud was the widow of the man who assassinated Northern Alliance leader Ahmed Shah Massoud two days before 9/11 on Osama bin Laden's orders.
Garsallaoui traveled with the cell to Pakistan and helped arrange for them to train in al Qaeda camps in Waziristan, according to court documents. In 2008 the NSA intercepted several e-mails sent by Garsallaoui to El Aroud in Belgium, according to two Western counterterrorism officials. Belgian officials needed the help of the Americans because the e-mails were sent via American Internet service providers, one of the officials said.
According to court documents in the subsequent trial, El Aroud and Garsallaoui had e-mail accounts administered by U.S. Internet access providers.
The documents stated that as early as December 2007, the FBI handed Belgian authorities a disc with information relating to these e-mail addresses that had been provided to the FBI by Microsoft and Yahoo.
According to court documents, e-mail information relating to the case was "provided voluntarily by the companies Microsoft and Yahoo, as authorized by the Patriot Act."
The documents stated that one of the reasons authorities grew alarmed that an attack was possibly about to be launched was that an electronic communication had been intercepted from a suspected cell member in Belgium to Garsallaoui in Pakistan on December 7, 2008.
When police moved in to make arrests four days later, they did not find evidence that a plot was imminent.
El Aroud and several others were subsequently convicted of being part of a terrorist cell. It is believed Garsallaoui was killed by a drone strike in Pakistan last October.