They probably should have made it clear from the beginning that anyone under 18 cannot enter into a NDA. Beyond that, it is a matter of state law.

This is going to be a growing problem as open-source continues to expand it's influence. How do you determine that a developer you have never seen or are not likely to have physical contact with is legally capable of entering into a contract? Up till now, it's not been a real problem, but this IS going to get ugly in the future as companies start to examine legal ramifications of open-source contracts.

If humans were honorable, we wouldn't be facing this issue, but let's face it, people suck.