No kidding. We didn't need a study to know that.
"We have just finished a study that shows how user interface design flaws allow users on Kazaa to share their personal files without their knowledge. In a laboratory user study, only 2 out of 12 subjects were able to correctly determine that Kazaa was sharing their entire hard drive. We looked at the current Kazaa network and discovered that many users are sharing personal information such as email and data for financial programs such as Microsoft Money. To see if other users on Kazaa were aware of this and taking advantage of users ignorance, we ran a Kazaa client for 24 hours with dummy personal files. During this time, files named "Inbox.dbx" and "Credit Cards.xls" were downloaded from our client by several unique users.
This is pdf
http://www.hpl.hp.com/shl/papers/kaz...aUsability.pdf