What, exactly, is an acceptable protest?

B.C. government officials have denounced some of the actions taken by protesters in recent days in demonstrations supporting Wet'suwet'en hereditary chiefs in their fight against a natural gas pipeline.

On Thursday, Public Safety Minister Mike Farnworth issued a stern warning to activists who have blocked entrances to the legislature and plan to shut down other government buildings. He said there will be consequences for those who "cross the line."

"What is not acceptable are protests that intimidate people, what is not acceptable are protests that harass people, what are not acceptable are protests that frighten people," Farnworth said.

But where is the line between acceptable and unacceptable? CBC News asked two experts on politics and the law to explain.

When does a protest 'cross the line'?

Government officials have alleged that public servants were bullied during Tuesday's demonstration at the legislature, and police say four people reported they were assaulted. No one has been arrested to date.

David Moscrop, a political scientist and post-doctoral fellow at the University of Ottawa, said a protest has clearly gone too far when someone has been physically harmed.

"I don't think standing in front of a politician who's trying to get into a building constitutes violence," he said.

Can protesters block roads and railways?

In Metro Vancouver this week, supporters of the Wet'suwet'en hereditary chiefs have shut down a major intersection for 16 hours and stopped the West Coast Express from carrying commuters into and out of Vancouver.

Vancouver lawyer Paul Doroshenko says blockades like this can be protected under the Charter of Rights, which guarantees freedom of expression.

"One of the most highly protected areas of freedom of expression is political expression, and this is pure political expression," he said.

But how long is a blockade allowed to last?

Blocking transportation infrastructure is defensible until it becomes a public nuisance, according to Doroshenko.

That's when the courts come in governments and businesses can apply for injunction orders, which police can then use to clear protesters.

"I think it's important for everyone to recognize that when you're being inconvenienced, this is someone else expressing their opinion in a lawful manner that they're entitled to do," Doroshenko said.