BEMIDJI -- A speaker on Internet etiquette told Bemidji High School students on Monday that they should conduct themselves online as if their grandma were looking over their shoulder.

Dave Eisenmann, a former teacher who has presented at schools across Minnesota the past several years, said students should treat one another respectfully when interacting online, and that content posted today will linger forever as signs of character. He spoke with two sets of students at the high school in the morning, and with parents at St. Phillip’s Church in the evening.

“It’s an exciting time to be alive,” Eisenmann told the students, citing Amazon’s prototype drones that deliver packages in 30 minutes or less, and 3D printers that spit out everyday objects.

“We should use technology positively,” he said.

Students used their cellphones to weigh in on poll questions: their gender, the social media platform they use the most, their experience with cyberbullying.

Eisenmann said he’s seen bullying change from the time he was in school, when students had to save their insults for face-to-face interactions.

“You’re living in a pretty stressful time,” he said. “You can be sleeping and be bullied, wake up and see that something about you has been passed around.”

Cyberbullying is increasing. Eisenmann said about 10 percent of Minnesota students polled two years ago said they had been bullied online. At the high school on Monday, 30 percent of students who responded to the poll said they had been cyberbullied, which Eisenmann said is typical today.

He challenged them to post online only what they would say out loud.

Another 80 percent of students said they had done something regrettable online.

Pornography, he said, is wiring the human brain to objectify the opposite sex, causing unhealthy behaviors when young people enter relationships. Eisenmann introduced the “grandma rule.”

But often, he said, students regret comments they make online or photos they send to a friend.

There’s no such thing as Internet privacy, Eisenmann told the students, but setting their social media accounts to “private” or posting more “positive” content -- like news articles and evidence of volunteer work -- can limit the damage.

More and more, Eisenmann said, employers and college admissions representatives are Googling students’ names and studying their social media accounts, looking for advantages one candidate might have over another.

Mistakes people make online aren’t “going to wash away like footprints in the sand,” he said.

Always be thinking about Grandma.