WASHINGTON — As Americans consider whether they are more safe or less five years after the Sept. 11 attacks, one thing is certain: They are being monitored by their own government in ways unforeseen before terrorists flew planes into the World Trade Center and Pentagon.
Within minutes of the strikes, U.S. law enforcement and intelligence-gathering authorities mobilized to find the culprits and prevent another attack.
They increased the tapping of Americans' phone calls and voice mails. They watched Internet traffic and e-mails as never before. They tailed greater numbers of people and into places previously deemed off-limits, such as mosques.
They clandestinely accessed bank and credit card transactions and school records. They monitored travel. And they entered homes without notice, looking for signs of terrorist activity and copying the contents of entire file cabinets and computer hard drives.
Authorities even tried to get inside people's heads, using supercomputers and "predictive" software to analyze enormous amounts of personal data about them and their associates in an effort to foretell who might become a terrorist, and when.
In the five years since the attacks, the scope of domestic surveillance has steadily increased, according to interviews with dozens of current and former U.S. officials and privacy experts.
Some of these programs have been debated and approved by the courts and Congress -- the traditional checks against intrusions on Americans' privacy, protected under the 4th Amendment.
Others have not. Some of them are operating without the knowledge or approval of judicial and legislative overseers, officials and experts say.
Two such classified programs have been disclosed by the media, over the objections of the Bush administration. One involves the National Security Agency's warrantless wiretapping of suspicious phone calls and e-mails into and out of the United States. The other is an effort by the Treasury Department and the CIA to monitor international bank transfers.
Privacy experts and even some ranking lawmakers in Congress say their efforts to learn about other suspected surveillance efforts have been blocked.
They believe that some of the activity is so secret that none but a small circle of top administration officials and operational support personnel know about it -- though notification of congressional leaders is legally required.
