If a Google employee reveals that he or she intends to leave because they have *accepted*–not received–an offer from a talent competitor like Facebook, in some cases they will be “walked off” so that they will no longer have access to Google’s proprietary information. More important than having that employee leave the physical building is shutting off their employee account; and most tech knowledge workers can’t perform their jobs without access to the company’s Intranet, VPN, or email.
Yes, I had a coworker who received an offer from Facebook and was asked to leave immediately by Google. It seems to be a common practice in the tech industry to avoid potential conflicts of interest.
Yes, I had a friend who received an offer from Facebook while working at Google and he was asked to leave immediately. It seems to be standard practice for Google to enforce this policy to prevent sharing of confidential information with competitors.