Me: Can you tell me a little about your research process for this paper?
Student: Oh, I didn't really do any research, I just wrote it.
Me: Are you sure?
Me: I'm asking because a number of passages in your essay are identical with an essay that can be downloaded from multiple web sites. Would you take a look and compare these two paragraphs?
Me: How do you explain this?
Student: I have a file-sharing program installed on my computer ... maybe it took a file off the computer without me knowing about it, and then installed it on all those sites?
(Damn, if only all that ingenuity had been applied to the assignment in the first place...)