A new anti-terrorism bill, which passed the House of Commons Wednesday night and received royal assent Thursday, revives provisions from the Anti-terrorism Act passed just after the Sept. 11 attacks and adds some new ones.

Some controversial measures, such as investigative hearings and preventive detentions, which some fear might violate civil rights, have been restored. Some new sections in the bill seem tailored to thwart the early planning stages of an act of terrorism.

Here are eight things to know about the bill passed this week:

1. Investigative hearings are reinstated

An individual can be forced to appear at a secret hearing without any charges being laid if authorities believe he or she has knowledge of a terrorist activity. The individual must appear and answer questions or risk being jailed for up to 12 months.

2. Preventive detentions are reinstated

An individual can be held for up to three days on suspicion of being involved with terrorism. Upon release, he or she can be ordered to uphold probation-like conditions, such as not contacting certain people, for up to 12 months, without ever being charged with any offence.

3. Both provisions are 'sunsetted' again

Both investigative hearings and preventive detention are "sunsetted" to expire in five years, as they were under the original 2001 law, and which is what happened in 2007. Under the new law, the government must explain annually why it's necessary to extend these measures.

4. New offences target foreign travel

An individual can be charged with leaving or attempting to leave the country with the intent of committing an act of terrorism. This provision could apply if someone travelled from Canada to attend a terrorist training camp overseas.

5. Acts committed outside Canada can be prosecuted

An individual can be prosecuted for hijacking an aircraft or endangering safety on a plane or at an airport in another country if that person is found in Canada.

6. Facilitating terrorism in another country is illegal

For instance, anyone who knowingly facilitates the communication of false information — such as by knowingly lending someone his or her cellphone, outside Canada, to make an emergency call about a false bomb threat against an aircraft — could, if found in Canada, face up to 14 years imprisonment.

7. Wiretapping provisions stay in place

In a terrorism case, authorities do not have to prove that electronic surveillance is a last resort. Wiretaps can stay in place for up to a year. People don't have to be informed they've been wiretapped for up to three years after the surveillance took place.

8. Some penalties are toughened

The penalty for harbouring or concealing a person known to have committed a terrorist act has been extended from a maximum of 10 years to 14 years in prison.