I came aross this article at wired.com.
Finlay Dobbie was a frequent contributor to Darwin -- the open-source core of Mac OS X -- until the company discovered he was a minor.
Citing its policy that members of its developer programs be at least 18 years old, Apple disabled Dobbie's Apple Developer Connection account, making it impossible for him to download developer tools or further participate in Darwin.
i guess the reason they did this is that they felt that the legal issues of a minor contributing to the open source project were too hairy. since he is not 18 he can not enter a legal contract which means he could later decide that he wants to keep the rights to parts of darwin he contributed which would put apple in a very difficult situation. still it seems apple could simply get his parents to cosign any legal documents and thereby bypass any hairy legal issues."Apple's response is very short-sighted and sad," he said. "They've forgotten their roots."