Here is another of those surveys that’s bound to cause some parents out there to lose a little sleep. In a recent national survey of teens and young adults, 21 percent of teen girls and 18 percent of teen boys said they have sent or posted nude or semi-nude photos of themselves.

The “Sex and Tech” survey of 1,280 teens and young adults was released Wednesday by The National Campaign to Prevent Teen and Unplanned Pregnancy and CosmoGirl.com. They results, organizers said, were disturbing:

“That so many young people say technology is encouraging an even more casual, hook-up culture is reason for concern, given the high rates of teen and unplanned pregnancy in the United States,” said Marisa Nightingale, Senior Advisor to the Entertainment Media Program at the National Campaign to Prevent Teen and Unplanned Pregnancy. “Parents should understand that their own notions of what’s public, what’s private, and what’s appropriate, may differ greatly from how teens and young adults define these concepts.”

Among the findings:

• 15% of teens who have sent sexually suggestive content such as text messages, email, photographs or video say they have done so with someone they only know online.
• Nearly half of young people (49% total, 39% of teens, 59% of young adults) have sent sexually suggestive text messages or email messages to someone.
• Teen girls who have sent or posted sexually suggestive content provide a number of reasons why: Two-thirds (66%) say they did so to be “fun or flirtatious,” half (52%) did so as a “sexy present” for their boyfriend, and 40% as a “joke.”