My daughter is starting to use her Chromebook more and more independently. I'm very happy she's developing the skills, but also nervous about who and what she might encounter. I am convinced the danger is overblown by far, but seeing how trusting kids are I know I have to be safe rather than sorry. They think the world is a safe and good place and while it's much better in western countries than, say, India or Iraq, truth is that the world is a dangerous world for little girls everywhere. The internet takes away some of the physical aspects (direct bodily harm) but there's enough things that can happen to ruin your mind, psyche, life, and some abusers are skillful to even get victims to expose or harm themselves, setting up further harm for a lifetime (think of all the teenage girls who's photos are shared online for decades, with many of their friends having seen them, and with facial recognition this can all only get worse).
I'm less worried for the boys. I'm also less worried about the 'sex stuff' they might see (say, stumble upon erotica, porn, fetish porn, etc) as all those will come with time. I'm more worried about violence and /r/watchpeopledie kind of things. Imagine a seven or ten year old that can't sleep after watching Caspar or Moana, encountering a video of an innocent person being pushed in front of a train, or lynched, or ... It's absurd to me how that's legal on the US platforms that prudely censor every nipple...
But beyond this, there's a categorical difference to seeing something and being urged/pushed/forced into seeing it and the other person taking some perverse pleasure from it, as described by the previous poster. Goatse is disgusting but funny to some degree, but being lured into someone's virtual torture or rape den...?
It's like upskirt porn - totally uninteresting from the sexual perspective, its all about power, abuse, invading in the private sphere and mind of the victim. I don't want to expose my kids to that risk. The most previous thing I have in my world are my kids and especially their minds.
I want them to explore the digital, but the powers of abuse unleashed online - it's just incredible. From the random middle aged man paying for child rape in the Philippines or pretending to be a 12 year old boy and tricking kids into revealing their lives up to the abuse among classmates, friends and strangers - the internet is a damgerous place for kids. And I can manage and anticipate some risks for my kids. I dread what my daughters' friends will encounter when their only protection is a barely digitally literate single mom.