An inappropriate picture of a Lakeville middle school student that circulated among classmates is under police investigation and has students lighting up social media with talk of multiple suspensions.

The school district released few details about the situation Thursday but said in a statement that officials had learned Monday of "a possible violation of another student's privacy using electronic means" at Century Middle School.

Lakeville Police Chief Tom Vonhof said the department is investigating a report that a photo of one student was shared among other students at the school. He would not characterize the photo, but many social media posts suggested that it was taken in a locker room.

"Because this is an active investigation, I can't say at this point how many people may be involved," Vonhof said.

The results of the investigation will be forwarded to the Dakota County attorney for possible charges. Vonhof said he couldn't speculate Thursday on the nature of those charges.

The case would become the latest prosecution of incidents across the country related to juveniles sending sexually explicit images by cellphone.

In Washington, three students were charged with disseminating child pornography after passing on nude photos of a classmate that went viral. The charges were later reduced to misdemeanors for telephone harassment.

According to the National Conference of State Legislatures, seven states passed bills related to such "sexting" messages in 2011.

Lakeville schools spokeswoman Linda Swanson said she could not confirm that students had been suspended or give any further information because of the ongoing investigation.

She did say that rumors that as many as 50 students were involved are untrue. The investigation involves fewer students, she said.

"I don't know where that number came from. Someone tweeted it, I think. It was not the Lakeville schools," Swanson said.

Discussion of the investigation was rampant on social media, where teens from Lakeville bantered about what had happened.

Chatter among Lakeville students on Twitter outlined a story of one girl snapping the inappropriate photograph of another in the locker room and then sending it to other students. Some students cracked jokes about siblings or friends who had been suspended from school as a result.

School board member Jim Skelly said he did not know any more about the incident but hoped it would provoke discussions at home about the perils involved in the reckless use of cellphones.

"It's a little unrealistic to think that they can't have cellphones in schools," he said. "Making sure that students understand the proper use is something that the schools can do."

Research has shown that students between 12 and 17 receive an average of 60 text messages per day.

With smartphones, students can snap a photo, send it to a friend and post it online within seconds.

"Because it's so easy, because it's so fast, there's not a lot of incentive to take those extra three minutes [to think], 'What's it going to mean to me or my school?'" said Susannah Stern, a professor at the University of San Diego who has studied adolescents and technology use.

She noted that adults send or post inappropriate things online, too, but their communications usually don't go viral so quickly.

"For teenagers, especially young teenagers, their peer group is such an important part of their everyday lives," she said. "It can travel so much faster within that individual's network."

Parents need to help kids understand the reach and permanence of text messages or online posts, she said. But most teens tend to wise up as they get older.

"It always troubles me when we point the finger at the teenager," Stern said. "It's like giving kids a car and then being surprised when there are some accidents."

Katie Humphrey • 952-746-3286