Let's imagine for a moment that you have a teenager who has heard about a place called YouTube. All of his friends are on the site blogging on video about their lives and sharing videos and basically having a good time. This same teenager who used to go outside and play along with his friends has now subscribed to them online and is talking to them through his webcam.
You, unaware of your teenager's growing obsession, decide to allow this to pass. Weeks go by, then months. The teenager you once knew holds a sour face at the dinner table and sometimes even appears to be upset when you ask him about school or real-life interests.
Being the concerned parent, you talk to friends about your teenager's changing attitude. They tell you stories about the site known as YouTube. You hear the words "bullying" and "hate comments". They tell you to check your teen's computer and search for clues for such definitions.
Somehow you find a way to get your teenager away for a few hours. You go through his email client program and find several messages from YouTube with the subject field of each with a rather negative and hurtful heading. You click on the link to his inbox on YouTube and find that he is still signed into his account.
What you see is horror beyond belief.
There are dozens and dozens of messages all of which speak ill of your child. Some even suggest that his life isn't worth living and that he should go and kill himself. You manage to find his main channel page and find comments of a similar nature there.
Worse still, you find that these people leaving the comments are the very friends that your child hangs out with.
You decide to be brave, suck in your gut, and watch some of the videos he recorded. The first few start out with everyday things: musical tastes, relationships, and some random videos of your child doing nothing. But the newer videos have a different tone.
The newer videos feature your child in a more depressed state and very sensitive. You notice some of them are linked in response to other videos. A mere click on the original video takes you to a channel of one of the friends your child has that you noticed in one of the nasty emails left in the child's inbox.