[awesome_dude]

Because wikipedia is editable by _anyone_ it's probably not the best for prisons - it would provide a means for communication that wasn't able to be monitored.

I mean, if you were in prison and had access to Wikipedia, I could edit, or put something on the talk page, that was a message to you.

You would look up the specific page, and get the message.

[stickfigure]

There are downloadable, offline versions of wikipedia.

[mulmen]

This is an excellent point. Wikipedia is explicitly not a primary source so any access to it should include the sources as well.