SunSpot.net has an article about the sentencing of a hacker who logged keystrokes on 14 of Kinko's public terminals and then used one of the captured logins to access someone else's home computer via GoToMyPC (somewhat like VNC or PCAnywhere). The hacker was caught because the actual owner of the computer was sitting in front of his machine when the cursor started moving around by itself.
In other instances, sensitive corporate data has been gleaned from the convenience terminals in hotel business centers.
Think about what you're doing before using a public terminal! You don't know who's watching!