From our discussion in the 11:00 class when Paul asked why older information isn't freely available online it occured to me after class that the main reason that many journal articles that are older (say, from the 1980's and 1990's) aren't online is because many are only available in print and it is a very expensive and time consuming process to digitize items and make them available.
Publishers can also sell these "backfiles" to libraries ($$$) so there's another reason that this stuff isn't all on the web for free.
