From inside America’s most secure prisons, 1993 World Trade Center bomber Mohamed Salameh wrote letters to a Spanish terror cell and to Arabic newspapers praising Osama bin Laden and suicide bombers, saying, "Anyone who rises up against American arrogance and tyranny and causes the Americans fear and trembling also are heroes.” He openly signed off "ADX penitentiary in Colorado" — known as "Supermax."
"Those who allowed this lapse to take place should really be fired from the Bureau of Prisons," says Sen. Charles Schumer, D-N.Y.
Alberto Gonzales, the new attorney general, told Congress Tuesday at an appropriations hearing that he's trying to find out what happened.
"There is an investigation ongoing about this matter," said Gonzales. "I would prefer not to say much more than that."
"There really needs to be a major looking at this by the administration and by the head of the Bureau of Prisons to make sure this does not happen again," argued Rep. Frank Wolf, R-Va., at the same hearing.
Prison officials say all communications at Supermax are monitored closely.
A Justice Department official says Salameh was "a low level guy," not under any special restrictions, and that his letters encouraging violence were deemed "generic stuff" and "no cause for concern."
But a former federal prosecutor says these letters are dangerous and help recruit terrorists.
"That they are permitted to communicate and aid and abet the current terrorist networks affiliated with al-Qaida is something that is just intolerable," says former U.S. attorney Mary Jo White.
Other convicted terrorists are under greater restrictions.
Ramzi Yousef, mastermind of the first World Trade Center bombing, has not been allowed to communicate with anyone other than his lawyer for 10 years. The "Blind Sheikh" — Omar Abdul Rahman — can communicate only with his wife and his lawyer. Yet, NBC News found a prison letter, purportedly written by Rahman in January, posted on an Islamist Web site. In it, he urges Muslims to rise up against the aggressors — code for Americans.
NBC news has learned that Spanish intelligence notified the CIA last fall about the bombers' letters, and the CIA told the FBI. Yet, there is no indication that any additional security measures have been imposed.