Police forces across Southern Ontario are bracing for what will be one of the busiest party weekends of the year.   St. Patrick’s Day festivities are already under way in many communities.

Last year the annual celebration fell on Saturday and the weather was warm.  Close to five thousand people hit the streets in Waterloo.  Over 100 charges were handed out but for the most part things were under control.

Unlike London where a St. Patrick’s Day party turned into a riot and a residential neighbourhood ended up looking like a war zone.  68 people were arrested and more 170 charges were laid.

This year, police have spent the past two months preparing for this weekend.

“We’re paying a lot of attention to social media,” says London Police Chief Brad Duncan.  “Part of our analysis last year was that there was a lot of movement on the social media front, and we’ve already got some intelligence that we are going to use on Sunday.”

Authorities say they will be paying special attention to the area around the University of Western Ontario and the Fleming Drive student enclave around Fanshawe College, the site of last year’s riot.

In Waterloo Regional Police are also getting ready for St. Patty’s Day parties and using every tool available, whether it’s on horseback, on foot, by car and now on social media.

Waterloo Regional Police Spokesperson Alana Holtom says social media will play a bigger role this year.

“We are trying something we haven’t done before we will be tweeting live from St. Patrick’s Day festivities.” Holtom tells CTV. “

Police will be using Twitter to send out safety message.   They will be tweeting from @WRPSTODAY with the hash tag #STPATTYSWR.

“The tweeting is meant to connect with people in the community.  It might be anything from crowd management strategies,” Holtom also says. “We might need to get emergency vehicle through groups of people so it’s another way for us to maintain our presence and connect with people.”

Police forces in Toronto, Durham, London and Waterloo Region will be increasing their ride spot checks Saturday night and Sunday.