University of New Hampshire researchers found. Their conclusions appear in February's Pediatrics, due out Monday. "It's beyond the wild West out there. You've really taken away the age of innocence," said Dr. Michael Wasserman, a pediatrician with the Ochsner Clinic in Metairie, La., who was not involved in the study. Online pornography was defined in the study as images of naked people or people having sex.

In the survey, conducted between March and June 2005, most kids who reported unwanted exposure were aged 13 to 17. Sizable numbers of 10- and 11-year-olds also had unwanted exposure - 17 percent of boys and 16 percent of girls that age. More than one-third of 16- and 17-year-old boys surveyed said they had intentionally visited X-rated sites in the past year. Among girls the same age, 8 percent had done so. The results come from a telephone survey of 1,500 Internet users aged 10 to 17, conducted with their parents' consent. Overall, 36 percent had unwanted exposure to online pornography, including some children who had willingly viewed pornography in other instances. The 2005 number was up from 25 percent in a similar survey conducted in 1999 and 2000. The latest survey has a margin of error of plus or minus 2.5 percentage points.

The Associated Press contributed to this story