The Act aims “to deter and punish terrorist acts in the United States and around the world, to enhance law enforcement investigatory tools, and for other purposes.” Senator Feingold voiced fears that the more controversial aspects of the bill would impact on the privacy of US citizens: “each of us cares as much as anyone about the fight against terrorism, but we want to make sure we don’t go beyond that goal and intrude on our civil liberties.”
The provisions most likely to raise such worries include:
- Expansion of "pen register" authority to internet communications, permitting law enforcement monitoring of "routing" and "addressing" information upon a mere showing of "relevance" to an investigation with virtually no judicial oversight. This new authority will likely increase use of the FBI's Carnivore system.
- Authorisation of "roving wiretaps" for intelligence surveillance, allowing the issuance of "generic" court orders that could be served on any communications facility (including universities and public libraries) that a surveillance target might use.
- Approval of government monitoring (without judicial authorisation) of the communications of "computer trespassers," even in some circumstances where the affected user has permission to use the computer system. Under the Act, “computer trespasser” means a person who accesses a protected computer without authorisation and thus has no reasonable expectation of privacy in any communication transmitted to, through, or from the protected computer; and does not include a person with legitimate access to the protected computer.
- Authorisation of searches without notification to the targeted individual ("secret searches"), in effect allowing police break-ins to private homes and offices.
- Relaxation of existing limitations on the sharing of surveillance and other information between law enforcement and intelligence agencies, removing long-standing protections designed to prevent government investigative abuses.
The House of Representatives had produced its own anti-terrorism bill, generally regarded as a more balanced measure and called the Patriot Act. The House bill, for instance, does not contain a "secret search" provision. Significantly, it contained a "sunset" clause that would terminate new surveillance authorities in two years unless they were re-authorised by Congress. However, this version was replaced by a later draft which comes much closer to the Senate bill.
In the US, a bill must be passed through both the Senate and the House of Representatives in exactly the same form in order to become the law.