Windsor police are reminding the public that officers monitor social media and take threatening posts seriously.

Police and a local school board locked down Walkerville Collegiate high school Thursday after a teen allegedly posted some tweets police called concerning and very serious.

Police claimed one tweet suggested a teen would shoot up the school.

Windsor Police Superintendent Mike Langlois wants the public to know that police are watching and recording what's being communicated on social media. Langlois warns there is no joking around on sites such as Twitter.

"At the end of the day, it's a very foolish route to take to, communicate through, the social media in that type of fashion, because you may very well end up facing serious criminal charges," Langlois said.

It's not just police keeping watch on Twitter. It's the general public.

Scott Scantlebury, spokesperson for the Greater Essex District School Board, said it was a student that raised the alarm about the social media post that eventually led to the lockdown.

"Someone came to the principal's office and reported to the vice-principal that there was a tweet that concerned them," Scantlebury said. "That's encouraging when that happens."

Scantlebury said the board tries to teach students to use social media responsibly.

Langlois says the police have also been actively warning the public about the potential legal problems of social media.

"Whether you're a youth or an adult and you communicate these types of threatening messages or threaten to cause harm or violence to another individual, and it's in social media, the likelihood is the police will become aware of it, and once we do, it's not a joke, and it will be taken very serious," Langlois said. "It's not as simple as just, 'Well I was joking around.' When you're on social media, you're speaking to thousands, if not millions."