The arrest of a Montreal man over allegedly hateful comments made on Twitter in the wake of the Quebec City mosque shooting is raising issues about freedom of speech.

Both the Quebec provincial police and Montreal police have reported a spike in calls about the use of hateful language since Sunday's attack in which six people died and 19 were injured.

The charges laid Wednesday are tied to a series of tweets by a Twitter user with the handle @Hermit_Spirit, who got into arguments online about Muslims on Tuesday evening.

A WHITE IDIOT KILLED 6 INNOCENT MUSLIMS.... in their HOMES.... none of those beheading happened anywhere near US SOIL, so fix ur thinking <a href="https://t.co/wzEurkoz5S">https://t.co/wzEurkoz5S</a> —@Hermit_Spirit

If u had more than half the useless brain that u do. u would realize 99% of the Billions of Muslins do not agree with those so-called rules <a href="https://t.co/BwCHEwNYXE">https://t.co/BwCHEwNYXE</a> —@Hermit_Spirit

Police say the comments went too far when the @Hermit_Spirit seemed to suggest that other Twitter users engaged in the argument should kill Muslims — and also threatened to kill another Twitter user in the string.

I am against all those things and I need you to prove you are also, by killing all refugees at the airport before they come rape your family <a href="https://t.co/Y5xiQReNql">https://t.co/Y5xiQReNql</a> —@Hermit_Spirit I need u to tell me how do we stop sharia law, before it hits US shores? I can only think of killing innocent muslims while praying, you? <a href="https://t.co/eYIxsGBLTw">https://t.co/eYIxsGBLTw</a> —@Hermit_Spirit

Antonio Padula, 45, was arrested overnight Wednesday at his home.

He was charged with uttering threats to an individual and public incitement of hatred against an identifiable group.

According to sources who spoke to Radio-Canada, when police arrived at his Kirkland home in Montreal's West Island area, Padula was incredulous, and he asked if they were there because of what he wrote online.

Padula was granted bail on Thursday afternoon. Under his bail conditions, he is not allowed to use the internet, not allowed to have weapons, and he must keep the peace.

He'll appear in court next on March 9.

Inciting hatred against Muslims?

Montreal human rights lawyer Julius Grey said he believes the case is an illustration of how freedom of expression is disappearing in modern society.

In an interview on CBC Montreal's Daybreak, Grey said making potentially problematic comments on the Internet can be more serious than simply saying them out loud to one person, due to the internet's reach and the potential for comments made online to be discovered and repeated.

My advice to everybody would be don't put anything other than very bland things on the internet. - Civil rights lawyer Julius Grey

Grey said that despite the fact the Twitter user @Hermit_Spirit used crude and violent language in the tweets, it appears the comments come to the defence of Muslims rather than inciting hate against them.

"On the internet, how do you judge whether the [writer] is serious or sarcastic?" he asked.

"We're still allowed to be sarcastic. We're still allowed to say to somebody, 'I'm so busy today that if you're late, I'm going to kill you,' and nobody thinks you're going to kill them."

Keep your comments online bland, lest they come back to haunt you, advises Montreal human rights lawyer Julius Grey. (CBC)

Grey said the incident serves as a warning that any use of vehement or clumsy language online could lead to criminal charges.

"My advice to everybody would be don't put anything other than very bland things on the internet," he said.

Conviction may be difficult

Sûreté du Québec Capt. Guy Lapointe said there have been more than 170 reports of hate speech since the Quebec City attack.

He emphasized that not all those reports will be investigated, but Padula's arrest should serve as a warning.

"Because they are behind a keyboard or an intelligent phone, they'll cross that line, and the words that they put up there go beyond what their thoughts are and then they end up in a situation where they might face charges," he said.

Former judge Suzanne Coupal says if he's found guilty, Padula could serve up to seven years in prison.

However, she said winning a conviction on these charges is not easy.