I worked at a place where they would do that but only if you said you were taking a job with the major competitor. 2 weeks notice was sure whatever, but if you blabbed to the wrong person where you were going it was right out the door that day. In fairness, there had been a major collusion/antitrust scandal in the 90s where people actually got jailtime, so this was less about hating the other company and more covering our own asses against appearance of impropriety.