Amegy Bank of Texas is successfully navigating the legal land mines that the brave new world of social networking Web sites can contain. Amegy and its longtime employment lawyer developed a policy to be followed when filling the 45 or so positions that open every month in the 2,000-employee company. That policy has not only served the bank well over the past year, but it's the cornerstone of an ongoing evaluation of how to best utilize online resources when it comes to smart staffing strategies.