"We have a number of people who are phoning in tips or have sent in clips from videos that they've seen on the websites, YouTube and Twitter and so forth, and our investigators are following up with all of that information," said London police Const. Dennis Rivest.
"We've been in the world of social media for a while now, but clearly this has been a terrific aid for us in our investigation and in identifying who all of the individuals are."
Eight of the 13 arrested so far are Fanshawe College students, who have been suspended and are facing expulsion. Police said they expected more charges to be laid as they went through video and witness statements.
Fanshawe College president Howard Rundle spoke out against the violence Monday, saying he was disappointed and angry over the massive street fire fuelled by an intoxicated crowd of about 1,000 revellers who attacked police and firefighters.
The college, he added, was taking the matter "very seriously" and conducting its own investigation, which included setting up a secure e-mail account to receive information and video.
Students have also started a Facebook page to identify suspected rioters, and that information will be shared with police, who have also set up a tip line.
"The actions of some of our students not only endangered themselves but put our emergency responders and our community at great risk," Rundle said during a news conference Monday.
"This is unacceptable. It will not be tolerated, it will not be excused, and we will not have those people as students of this college."
Social media has proven to be useful tool for police forces in similar investigations in the past, including the Stanley Cup riot in Vancouver last spring.
Police in Montreal also said last week they would use video and photos sent to them by the public to make more arrests after an annual anti-police brutality demonstration in that city once again turned violent.
Christopher Schneider, a sociology professor at the University of British Columbia who has followed the Vancouver riot, said social media was changing police work because it provides a context and creates data investigators can use to prosecute.
"The police are using this piece of the puzzle to tell people, like they did with the Vancouver riots, 'We've got your images, we've got your pictures, you better come forward now, maybe the charges will not be as heavy-handed on you if you do that,'" he said.
But it also creates more work for investigators because images posted by a third party on sites like YouTube have to be authenticated, and a tweet or Facebook post doesn't prove someone was actually at any given event, Schneider added.
"(In the Vancouver riots) the data was used, but what it does is complicate police work because it slows it down even more, in a society where we expect things operate even more quickly than they have in the past," he said.
Hundreds of Fanshawe students were said to be involved in the riot, which took place in a neighbourhood described as a student enclave notorious for its parties. It has been the site of previous disturbances, although none as large as the weekend outburst.
There were also students there from local high schools, "much too young to be out of the watchful eye of their parents", as well as some from other institutions and people from outside London, Rundle said.
The riot, he added, points to issues around the development of student enclaves in a city and deeper social problems such as binge drinking, all of which need to be looked at.
"We need to focus on working together with police and the city to ensure this never happens again," Rundle said.
No one was seriously injured in the riot, which cost an estimated $100,000 in damage and drew attention outside of Canada after it was picked up by the BBC and several other news outlets in the U.K.
London police Chief Brad Duncan has said it could have turned into something far worse, and resulted in someone being killed.
— By Romina Maurino in Toronto
Also on HuffPost