A new phone app is causing a social media uproar and not in a good way.

It’s called "Yik Yak", an anonymous forum that is being used right here in this city by some students to bully, threaten and dare other students to break the law.

Ottawa Fire Services believe students were using Yik Yak yesterday when fire alarms were pulled four times at four different high schools, leaving hundreds of students standing in the cold.

But students are telling CTV News that is not the worst of it.

A fire truck screams out of the bay at a fire hall in the east end of the city. It is a scene that will be played out four times within two hours of each other. The first one was at Beatrice Desloges Catholic Highschool on Provence just after lunch. Students say the alarm was pulled after a post to a social media site called "Yik Yak".

‘Someone was like if I get 100 likes, I will pull the alarm and it happened,’ says Grade 12 student Virginie Charland.

That was at 13:05. Ottawa Fire Services say another call came in at 13:29 at St Peter High school on Charlemagne Boulevard a few blocks away. Then, at 14:15, a third one at Gisele Lalonde High School on Millennium Boulevard. And less than half an hour later, at 14:41, a final call for Sir Wilfred Laurier on Tenth Line Road. All in Orleans and all within a few blocks of each other. It is believed that all the fire calls were prompted by dares through Yik Yak, an anonymous messaging app that allows viewers to see messages posted within only a few kilometres of each other. What was supposed to be a fun way to connect and share information seems to have turned into something more sinister.

‘These students are pulling alarms at schools in their own areas,’ says Marc Messier with Ottawa Fire Services, ‘so basically they are putting their own families at risk because it could be their houses on fire or one of their family members having a medical emergency.’

Pulling a false alarm is criminal, but that's only one way this app is being used for harm.

‘It’s just hateful rumors that are posted,’ says 16-year-old Michelle Walker, at student at St. Joseph High School, ‘People didn't want to come to school because of stuff that was being posted on the page. Hurtful stuff.’

These students say students are using Yik Yak to cyberbully.

‘What they need to do is make children and parents aware of what the consequences are,’ says 17-year-old Renée Ouellette,’ and get police involved and ban it. Get rid of it, shouldn't exist.’

Yik Yak was launched a little over a year ago. Since then it has been linked to harassment cases, banned on some US school campuses and cited in some arrests for violent threats. Now, 77-thousand people have signed a petition to shut it down.’

Ottawa's Catholic and public school boards have blocked Yik Yak on their wifi networks, though students with data can still use it. It is free and simple to download.

‘Takes about five seconds,’ says Michelle Hunter, ‘for someone to write a hateful comment.’