The FBI is asking for the power to perform "widespread monitoring of 'illegal' Internet activity":

The suggestion from FBI Director Robert Mueller, which came during a House of Representatives Judiciary Committee hearing, appears to go beyond a current plan to monitor traffic on federal-government networks. Mueller seemed to suggest that the bureau should have a broad "omnibus" authority to conduct monitoring and surveillance of private-sector networks as well.

...Mueller said his idea "balances on one hand, the privacy rights of the individual who are receiving the information, but on the other hand, given the technology, the necessity of having some omnibus search capability utilizing filters that would identify the illegal activity as it comes through and give us the ability to preempt that illegal activity where it comes through a choke point."

...If any omnibus Internet-monitoring proposal became law, it could implicate the Fourth Amendment's guarantee of freedom from unreasonable searches and seizures. In general, courts have ruled that police need search warrants to obtain the content of communication, and the federal Wiretap Act created "super warrant" wiretap orders that require additional steps and judicial oversight.