How can we help children learn to handle free access to media?
The first thing to realize is that this is not a new problem. The ubiquity of the Internet, its breadth of information, and its connectivity to such a vast userbase is new, but the base problem is not new.
One of the earliest media of communication is storytelling. Still today we find ourselves questioning the best way to handle our child's access to stories:
The school has assigned reading I feel is inappropriate for my son to read. How do I approach this problem with the school and with my son?
The invention of writing brought information out of the oral realm into something that could be preserved across time and space without having to be transmitted directly from the source of the information. As more people gained access to writing, our ancestors had to ask themselves
How can we help children learn to handle access to reading and writing?
Today there are various approaches to this problem. We naturally teach our children to take care in what, how, and to whom they write. We concern ourselves with what our children read and have open discussions with them about it.
The invention of printing didn't really change any of this. All it did was increase the access to information.
Television did seem to bring a new set of problems: it presented information in audio/visual form, it broadcast it over large distances, and it didn't immediately open up access for everyone to broadcast. The latter two are really nothing new. Access to information increased again, and like most new things the more powerful had greater control initially. Today we are still dealing with the repercussions of the audio/visual format:
At what age should a child be introduced to the Television?
How is the Internet different?
The Internet is everywhere and it is for everybody, but how is it really different? It is instantaneous. Once given access to an unrestricted device connected to the Internet, our children can immediately gain access to whatever they want and more. Even if you restricted your home devices, Internet-connected devices are practically ubiquitous today. It is not difficult for your child to visit the neighbors and be on the Internet before you even know they've left the house (depending on their age).
What's the point?
I don't think the instantaneous nature of the Internet changes much except that it makes it all the more important that we establish open communication with our kids. If we form the habit of sharing what we (parents and children) experience early on, then we will be prepared (with an understanding of our child's experience) to handle their issues and they will be prepared to share their issues when they occur because they will know we're ready to listen.
Case 1: Gory Flash Game
Open Communication Outcome 1
Child: I want to play some flash games.
Parent: All right, what were you thinking of playing?
Child: Oh, I was going to try out this fighting game on Freshdirt.
Parent: I think that game's pretty gory.
Child: Hm, I didn't know that. Maybe I'll try something else.
Alternate ending:
Child: I saw that it might be a little gory, but I think it's just comic violence.
Parent: Well, if you're sure it won't bother you, why don't we check it out together and see why it's so gory.
If the game covers mature themes like "Kill Your Boss", it might be a good time for a discussion about how that kind of thinking isn't healthy.
Open Communication Outcome 2
Child: I just clicked on a flash game, and it was pretty scary.
Parent: Well, what happened?
Parent and Child can discuss what was disturbing. Parent will probably look at the game too to know more specifically what occurred.
Open Communication Outcome 3
Parent: What did you do for fun today?
Child: I played some Internet games.
Parent: Did you find anything interesting?
Child: Well, I did play this one game. It was kind of gory though.
Further discussion, as above.
Notes
Depending on age, this much freedom does not have to be given. As this may be particularly relevant to the title question, see "Easing in access" section.
Case 2: Pornography
Parent: I've noticed you've been spending a lot of time in your room on the computer lately.
Child: Well, I'm just surfing the web.
Parent: With your door closed?
Child: To be honest, I'm exploring a little bit of those things we talked about.
Parent: There's a lot of scams and malware out there, and sometimes you may stumble into more than you bargained for. Can I give you some advice?
Parent explains to their satisfaction what the best practices regarding Internet porn are.
Case 3: Talking with Strangers
Child: I met somebody cool on the Internet.
Parent: What do you talk about?
...
Parent: Don't forget to be careful with how much information you give out.
Alternate ending:
Child: They want to meet me.
Parent: Well, I think we need to get to know them a little better first, and we should probably meet them together.
Easing in access
As your child gets older, there will naturally be less direct supervision of their online activity, but how exactly should this happen?
In regards to mature content like violence, sex, and drugs, it is probably a good idea to have a safe list of sites to visit with your children. As they get older, you give them more freedom to visit the safe list with less direct supervision. For things not on the safe list, you may view them with them the first time or preview them in advance. By making the safe list a social device that you both refer to rather than a technical restriction, this shows that you trust them to make decisions about their own safety as they learn from you how to manage it. You may start out using the Internet with them at all times at a young age, then when they are older they may use it solo in the same room as you. Eventually, they graduate to using it on their own terms but with time restrictions, and then finally they start to learn how to make their own time management decisions.
In regards to communication with strangers, you should be clear with your children early on about what kind of information is dangerous to share with people--and who you can share what with. When they start talking with people online, you should probably be with them at first. As they get older, you may ask to be introduced to their online friends but not have to be present for the whole conversation. If they ever want to meet someone in person, you should be clear that you want to go with them--at least at first.
Is this my opinion?
Yes, but I tried to make it as grounded in the prevailing views of experts as I could, as far as I see it, and also open to many different applications. I am open to criticism and may choose to adopt views of others into my post as I see fit. Leave a comment if something sticks out to you.
Personally, I think by the age of 15 (at the latest) you should have your child ready for unlimited access to the Internet alone whether you like it or not, because they most likely will find their ways to get it no matter what the consequences.
Disclaimer
My answer assumes a knowledgeable parent--that is, a parent who knows about the Internet themselves and its risks and how to protect yourself. I don't think that is a problem with my post. A parent should become knowledgeable about anything before they set themselves as the point of contact for that issue with their child.