A Vaughan, Ont., teenager convicted of careless driving after boasting online about his speeding exploits has become the latest cautionary tale for social media users.

Vladimir Rigenco, 19, found himself the target of a police probe several months ago, when a U.S. citizen called in a tip stemming from Mr. Rigenco's post on an Internet forum for BMW fans. In it, the young man boasted about driving 100 kilometres per hour above the posted speed limit on Apple Blossom Drive, a residential road in Vaughan.

Now, Mr. Rigenco has been convicted, sentenced last week to a six-month driving prohibition and 12 months of probation. He must also complete a remedial driving program and pay a $1,000 fine.

Alan Ackerman, a expert in privacy and social media with the University of Toronto, said the young man's "exhibitionistic comment" illustrates a fundamental knowledge gap about what is public and what is private.

"It looks like he didn't really anticipate what that would set off," Mr. Ackerman said.

York Regional Police Constable Serguei Barmakov, the arresting officer in Mr. Rigenco's case, said it all began with a tip from an American citizen, which prompted police to visit the 5 Series Forums, an online discussion tool for BMW enthusiasts.

"As a result of that, we observed this character boasting his dangerous driving behaviour," Const. Barmakov said. "A full-scale investigation was launched to [determine] whether there was any substance to the words."

Mr. Rigenco's posting indicated he was travelling 140 km/hr in a 40 km/hr zone on March 15, Mr. Barmakov said. Armed with those details -- and with photos of the suspect and his vehicle taken from the forum -- police canvassed the relevant area in Vaughan for witnesses, and found several.

"It appears that this was a repeated behaviour," Const. Barmakov said, though the police probe only focused on the one incident.

Police charged Mr. Rigenco in April with dangerous driving, a criminal offence, but charges were later downgraded to careless driving under the Highway Traffic Act in light of the 19-year-old's guilty plea.

Const. Barmakov said this is the first time he has launched an investigation because of an online posting, calling it evidence of a new era.

Toronto-based traffic lawyer Volga Pankou noted that such a posting, on its own, would likely not be sufficient evidence in court to prove careless driving.

"If the guy who posted it said, 'No, it was just a joke, I didn't do it,' then police would have to prove during the trial if they had any other evidence," Ms. Pankou said.

Mr. Ackerman says this is just the latest example of youth landing themselves in hot water because of their attachment to modern social media tools. There are cases of people being discovered for faking "sick days" at work after pictures of partying emerged on Facebook; cheating and infidelity have similarly been uncovered.

"I think there's really been a breakdown in the sense of what is and isn't private," Mr. Ackerman said. "It's a very profound cultural development, let alone having legal ramifications."

As for Mr. Rigenco, Const. Barmakov says the teenager readily admitted to his actions and has since shown remorse.

"He obviously understands the dangerous behaviour and the consequences it could potentially result in," Const. Barmakov said. "He was actually glad he was stopped before something terrible would happen."