Not a stupid question, but there must be a stupid answer:
Your Web browser crashes because some applet or other function on a page just tied your computer into knots. Upon relaunching the browser, it helpfully tries to restore the fault condition by re-opening the last visited page and all its chaos. Some OSes will do this, too, upon restarting.
Seriously, what the heck is wrong with coders that they think this is a great idea? (And it's always the default condition, meaning you have to opt-out of it.)
Do you think the person that stole Tom Brady's Super Bowl game jersey last Sunday that is supposedly worth about half a million dollars is crapping their pants right about now?