One of the ways that faculty teaching online attempt to insure the integrity of their testing is by requiring students to download, install, and access the test through the silly Respondus Lockdown Browser.
This browser, among other things, requires that you not be running in a virtualized environment, that no other app that could be considered remote access, or multi-thread aware be running (it will ask you to shut these apps down on launch if it detects them), and that you complete all interaction during the testing session through the interface that this browser provides.
Ostensibly this serves to protect the integrity of the test by forcing test takers to use only the knowledge in their head rather than hitting up Google or Wikipedia for additional information. Somehow, this makes the testing more reliable, and makes faculty more comfortable with allowing testing online. Because we all live in single computer homes where things like internet capable phones, iPods, iPads, XBox 360s, PS3s, and hell – even televisions somehow magically don’t exist if Respondus Lockdown browser is running.