Declaring "violent jihadism" a danger to Canadians at home and abroad, Prime Minister Stephen Harper unveiled details of his government's latest bid to boost the powers of Canada's law enforcement and intelligence agencies during an appearance at a Richmond Hill, Ont., community centre.

If passed, the government's Anti-Terrorism Act will:

Lower the threshold of proof for arrests.

Give Canadian Security Intelligence Service the power to "counter-message" or "disrupt radical websites and Twitter accounts," whether in Canada or elsewhere.

the power to "counter-message" or "disrupt radical websites and Twitter accounts," whether in Canada or elsewhere. Allow CSIS to apply for a court order to remove terrorist propaganda from the Internet.

to apply for a court order to remove terrorist propaganda from the Internet. Allow for some court proceedings to be sealed.

As reported by CBC News Thursday night, the new bill would give CSIS the authority to monitor, track and even preemptively disrupt the activities of suspected terrorists and terrorist sympathizers.

"Violent jihadism is not just a danger somewhere else," Harper told the crowd in Richmond Hill.

"It seeks to harm us here in Canada — in our cities and in our neighbourhoods, through horrific acts, like deliberately driving a car at a defenceless man or shooting a soldier in the back as he stands on guard at a War Memorial."

Canadians, he said, "are targeted by these terrorists for no other reason than that we are Canadians. They want to harm us because they hate our society and the values it represents."

Violent jihadism "is not a human right," Harper stressed. "It is an act of war, and our government's new legislation fully understands that difference."

The legislation would also expand the spy agency's ability to take direct action to counter potential threats, from cancelling plane reservations of those suspected of wanting to join the Islamic State of Iraq and Syria (ISIS) or other extremists groups overseas, to blocking financial transactions linked to suspected terrorist activity.

Under the current regime, those operations are handled by the RCMP, which government officials say can result in costly delays that can hinder the agency's ability to act swiftly to stop an imminent attack.

Court authority to be required

Those new powers will be accompanied by increased oversight, however: the agency will be required to get court approval before flexing its new muscles.

CSIS agents would not be given the power to arrest or detain Canadians, which will remain the exclusive purview of the RCMP and local police.

The new bill includes potentially controversial provisions that would make it a crime to "knowingly advocate or promote the commission of terrorist offences."

It would also give judges the power to seize "terrorist propaganda" or order it to be removed from the internet.

Civil liberties groups have expressed concern that such a move could have implications on freedom of speech.

The bill does not, however, seek to ban the "glorification" of terrorism, which had been widely rumoured to have been under consideration by the government.

Prime Minister Stephen Harper addressed reporters' questions on his new anti-terror legislation 15:48

Asked by a reporter how he could guarantee new measures wouldn't conflict with "basic civil liberties," the prime minister said there was "considerable oversight," but added that the premise of the question was wrong.

"This is really what we get from our opposition," he added.

"Every time we talk about security, they suggest that somehow, our freedoms are threatened. I think Canadians understand that their freedom and their security more often than not go hand and hand. Canadians expect us to do both, we are doing both, and we do not buy the argument that every time you protect Canadians, you take away their liberties."

'Radical expansion' of powers 'real danger to Canadians'

The B.C. Civil Liberties Association has already come out against the proposed legislation.

"This radical expansion of national security powers is not sound security policy and presents a real danger to Canadians," policy director Micheal Vonn warned in a news release issued shortly after the bill was made public.

"Criminalizing people's words and thoughts is misguided and won't make Canadians any safer," she added.

"We will be less free, less democratic and less likely to know who to keep an eye on. This new law will impose a broad chill on legitimate political speech without enhancing public safety, and is likely unconstitutional."

Former CSIS assistant director of intelligence Ray Boivert told CBC News that giving the agency more power to disrupt in cases that involve "an immediate threat to life" is "very, very necessary."

But he warned that such measures won't come cheap.

"They are going to need more resources," he said.

"I know from being a former insider, they're maxed out. They are so tapped out, and ... they have closed down so many other investigations that are still rather important."

Increasing those resources must be the next step, he told CBC News.

"Get your chequebook out, folks because I think that's just a reality."

The government is also expected to propose new measures — and funding — to combat radicalization and recruitment efforts, particularly those targeting youth.

Speaking to reporters from Sudbury, New Democrat Leader Tom Mulcair hinted his party hasn't yet decided whether to support the bill.

"It's important to be able to protect our rights at the same time as we're protecting our safety," he said.

"We are capable of doing both at the same time and we'll make sure that this bill ensures that, and we'll ask the appropriate questions."

NDP Leader Tom Mulcair says the government can protect Canadians' rights while ensuring their safety, adding the RCMP, CSIS need the resources to do so. 1:06

Liberal public safety critic Wayne Easter said his party supports "all reasonable measures" to keep Canadians safe.

"We understand that, in order to fight terrorism, police agencies and security agencies need the tools to keep pace with the times, so they can challenge those that would do Canadians harm out there," he told reporters Friday afternoon.

The Liberals will be reviewing the bill at caucus next week, he said.

"We're not going to get into the details of the bill at this point in time — there's five major sections in this bill as you know, some are fairly extensive powers," he noted.

"We're going to be talking to experts over the weekend. I will be reporting to caucus next week. We would certainly want to see robust hearings into this piece of legislation."

Although the bill itself had to be tabled in the House of Commons, the logistics for Friday's announcement strongly suggest that, as far as the government's strategy for selling the contents to Canadians goes, the main event was the prime minister's announcement in the Toronto area.

Harper was flanked by Public Safety Minister Steven Blaney and Justice Minister Peter MacKay, the lead ministers on the anti-terror file.