This thread is a good argument against take-home tests (if the way the questions were worded is any indication). If books and libraries are the only available sources, it takes more creative thinking to find the answers and it also makes it more likely that the person will actually learn the material instead of finding it and compiling it on paper or in a file. Presenting the material and knowing it are two completely different things.
The problem with having all of the information at one's fingertips is that, if this method of searching every fails, a whole lot of people will be helpless.
If the instructor cares about plagiarism, a bibliography will/should be required.
Oh, wait- a bibliography is presented when books are the source. Do they still use books in schools?