OTTAWA -- Academics and civil liberties advocates are telling senators the Liberal government's sweeping national-security bill doesn't go far enough to protect the rights of people ensnared by Canada's no-fly list.

The bill takes aim at the recurring problem of mistaken no-fly list name matches involving youngsters.

Several witnesses are urging a Senate committee to bolster the no-fly appeal process by assigning a special legal advocate, one allowed to see secret evidence, to assist people barred from getting on planes.

The bill would also limit -- but not eliminate -- powers that allow the Canadian Security Intelligence Service to actively disrupt terror plots.

It opens the door to new paths for security services in data-crunching and cyberwarfare, and enhances accountability and review through creation of a super-watchdog.

The legislation would also tighten provisions on information-sharing among federal agencies, redefine terrorist propaganda and narrow a general prohibition against promoting terrorism offences to the crime of counselling someone to commit a terrorist offence.