I'm doing it because Laurel's figured out how to do just enough with my computer to really irritate me. We initially thought the heat or power fluctuations might be causing my system to reboot, but it's become obvious over the past two weeks that she's been repeatedly going to my computer when I'm in another room and doing some combination of rebooting, closing all my open applications, opening the coloring pages folder on the desktop (since moved) and leaving a trail of open image and/or printing wizard windows and sending scads of files to the print queue. (I keep the printer off by default since she figured out it could print coloring pages.)
Today was the last straw -- while I was cleaning her potty in the bathroom after she used it, she closed everything I had open, opened a number of coloring page images in Paint and printing wizard windows (which is actually a handy feature of XP if you're not a four-year-old), and changed my wallpaper to some terrifying Wiggles coloring page image.
For punishment, she's lost outside time today and her DVDs went back to Blockbuster a day early (just as well, I was starting to hate Bob the Builder). I am Not Amused.