An FBI agent testified Thursday in the Jose Padilla terrorism case how members of an alleged Islamic extremist support network used code to disguise their conversations, substituting words like "tourism" and "football" for "jihad." The agent, John T. Kavanaugh, said participants suspected they were being overheard by government officials and urged each other not to openly discuss sensitive matters over the phone. The wiretap intercepts played for jurors Thursday mostly involved Padilla's two co-defendants Adham Amin Hassoun and Kifah Wael Jayyousi, although one call purportedly mentioned Padilla by his alias of "Ibrahim." All three are charged with being part of a support cell for Islamic extremist groups worldwide, including al-Qaida. Padilla, a US citizen held as an enemy combatant for three-and-a-half years, is accused of filling out a form to attend an al-Qaida training camp in Afghanistan.