Interesting thread, this.
I sometimes wonder how my parents would have felt about me being on the internet, had it been around when I was a kid. I suspect that my mother would have been extremely suspicious of it, given that she was a confirmed technophobe (she never even got the hang of programming the video recorder). In contrast, many parents these days, and certainly in the not too distant future, will have used the internet frequently themselves and therefore be able to take a sensible approach towards their children's use of it. As others have said, it is little different from real life - one simply needs to exercise a little common sense regarding the disclosure of personal details etc and it's totally safe. Indeed, it's clearly a lot safer way of meeting total strangers than in real life, given that those that you are speaking to are not physically present.
My own children are still too young to start surfing the web or joining forums. When they are a little older, though, I would personally have no reservations about them frequenting sites such as this. In fact, I hope that I will be able to trust them to use the internet with limited (parental) restrictions, although that will depend on me being able to trust them to use it safely and sensibly. Which in turn depends upon my wife and I properly educating them in this regard, plus their own inclination to behave responsibily. Well, we shall see ...
I agree with those who have pointed out that one should make sure of discharging real life obligations (homework, work, chores etc) before rewarding oneself with a Downs session. Although I will have to clean up my own act before preaching to my children on this, since there are times when I have spent far too much time here. Having said that, the demands of family, work etc clearly always come first for me (as my absence for most of the previous month testifies).
As for the comments made concerning parties, alcohol etc, I do feel some slight alarm at some of the more extreme positions that have been taken here. However enjoyable (and, in some respects, educational) the Downs might be, it can, to my mind, never match up to real life interaction. I hope that people aren't letting the extreme behaviour of those they see indulging in wild parties, drugs etc letting themselves be put off enjoying a healthy social life. You really don't have to go wild to have a good time, you know. As HerenIstarion says, most things are good in moderation (there goes Saucepan not practicing what he preaches again, as he works his way through a fine bottle of wine
).
One final (off-topic) thought. I find it amazing how much us Downers seem to share interests in common (in addition to Tolkien of course). Like Enca and Feanor, I was a complete dinosaur nerd in my younger years. By the age of 8, I had made up my mind to be a Paeleontologist, which was a never-ending source of confusion for those who asked me what I wanted to be when I grew up.
(Alas that I did not follow my childhood inclination.) And it's not just dinosaurs either. The Beatles' music and Monty Python both seem to present a common a link between many Downers too. Perhaps there is some explanation for a link between these things and Tolkien's works ...