As Canuck fans rioted on the streets of Vancouver Wednesday night, two Facebook groups sprang up amid the mayhem — one encouraging Vancouverites to clean up after the riot, and another hoping to identify the instigators.

Rioters took to the streets after the hosting Canucks lost the Stanley Cup final to the Boston Bruins 4-0.

Disgruntled fans burned cars, set fire to trash cans and looted several downtown stores, throwing the city's downtown core into chaos for several hours following the game.

But those opposed to the riots took their views online, joining social media campaigns to express their disdain.

A Facebook campaign that aimed to identify rioters and looters had attracted almost 20,000 people in less than 12 hours.

Witnesses were encouraged to post pictures of rioters in the act, in the hopes that they might be recognized and identified.

"People need to be held accountable for their actions and face the consequences under any circumstances," Jaime Porteous wrote on the group's Facebook wall.

"Prosecute the thugs," wrote Lorraine Bennett. "Clearly they hate the Canucks, they hate Vancouver."

A second Facebook group launched Wednesday called for Vancouver residents to clean up after the riots.

The "Post Riot Clean-Up — Let's help Vancouver" group had more than 12,500 people Thursday morning saying they would attend.

"Invite all of your friends! Let's see if we can get Vancouver looking like a new city by noon Thursday!" says the page creator, Smitty Smith.

A new site dubbed the Vancouver 2011 Riot Criminal List has been created on the microblogging service Tumblr, calling for pictures to help identify rioters.  

Police are asking anyone with video evidence, photographs, or witness accounts to contact them.

Police are getting lots of help from the public in tracking down people who took part in the riot, Vancouver police Chief Jim Chu told reporters at a news conference Thursday.

"By 5 a.m. this morning we had 120 tips on the tipline. Members of the public are sending us their videos and we are adding those to the thousands of minutes of video that we shot ourselves. We are fully committed to tracking down the criminals and arresting them for the crimes," he said.

CBC's Meera Bains walked through some of the worst-hit areas later in the day and saw that the community response wasn't just online.

Dozens of people were stopping by Granville Street and West Georgia to write messages and help clean up.

A home-made sign in Canucks colours said "On behalf of my team and my city, I'm sorry."

Tia Mar said she saw posts about the cleanup on Facebook and decided to come down and help.

"I couldn't even sleep at 6:30 in the morning," Mar said. "I'm like, I've got to do something about this."

Some businesses were handing out bottles of water to volunteers and the city said the response was overwhelming, Bains said.

Bains said the city was much cleaner later in the day, but she noted that there is still a lot of damage and many boarded windows downtown.

With files from The Canadian Press