Then one designer put in his two weeks and spent the majority of the time downloading all the site files for all of the sites the company had built over the two years he was there. We're talking hundreds of static sites where he took the all the design docs and static HTML/CSS/JS files one would need to recreate them somewhere else.
Instead of going after the guy legally, they passed and then instituted the same policy. You put in your two weeks? Nah, you're out the moment you hit send on that email. Manager alerts security, who then come over to your desk. You get your jacket and whatever you walked in with and get walked out. The one designer totally ruined the company from ever letting someone stay for their two weeks.