Richard Clarke in his book Cyber War calls for some of the same kinds of controls. He calls for banning attacks on civilians, especially the banking system. He also calls for arms inspectors and an obligation of nations to assist in finding the source of attacks that come from within their borders. He calls for a "Cyber War Limitation Treaty" that would also ban putting logic bombs in civilian infrastructure. I really liked this part of the book.

peace,

    isaac

The experimental Tearline Wiki system we've developed at Galois might suit your needs. Inside the firewall, you use MediaWiki with the Tearline system, and get a combined view of your internal wiki(s), possibly different wikis on different sub-nets, and you can integrate it with Wikipedia or other internet-based wikis to get the global context of the article.

As others have said, integrating your content with other people's content can be a legal issue.

Contact me if you want more information on Tearline :)

peace,

    isaac

I can illustrate the concept of a null-free language with examples from Haskell.

With Haskell types, you can specify all the valid values of a particular bounded type (the same is true for non-bounded types, but its more obvious for bounded ones):

data Day = Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday

Something of type "Day" cannot be NULL. It must be one of the days of the week. It's impossible to construct a value of a "Day" type without "assigning" it one of these values.

But then what if you want to handle a case where it might be none of these? There's another type for that called "Maybe", and you can wrap "Day" (or any type) in "Maybe" to indicate that it might be none of these. So "Just Monday" is a value simultaneously indicating non-null, and providing the Day value. "Nothing" indicates NULL or "none of the above".

For instance, if you write a function which gives the next day of the week, given a day of the week, it should input Day and output Day. It doesn't make sense for either its input or its output to be NULL. That is, it should have type "Day -> Day".

But if you want to handle for instance, a case of user input or parsing, where they might not give a valid day, then you should use the type "Maybe Day" or something similar.

Values of "Nothing" in Haskell roughly correspond to NULL except that the type system differentiates cases where something might be NULL and cases where something promises not to be NULL.

This turns out to be a useful distinction :)

peace,

    isaac