The other problem that I am sure most parents are not aware of is young people appearing nude (or even having sex) on web cams and broadcasting them over the internet.
There are loads of these "webcam" sites (I know because my son visits them and I often "tidy up" his computer when he is at work so know what sites he visits).
And I have to say some of these people look very young (maybe 14 or 15).
How many parents are aware their son or daughter, maybe as young as 13 or 14, are stripping off and displaying their "bits" over the internet.
And often these are recorded and stored on web sites to be downloaded by anybody.
I believe this is called Sexting (though this is mostly between mobile phones not sure if it applies to between web cams and computers)
http://en.wikipedia.org/wiki/Sexting
If a parent has a young son or daughter who has a laptop or webcam in their bedroom you should try and check up what they are actually doing.