Charlotte Mecklenburg Schools has dropped chain-link fences from its security plan. Tuesday night, the school board approved a revised plan that totals $20 million. It includes adding 4,000 cameras to schools, installing buzzer systems with intercoms on doors, giving schools software that can do instant background checks, and creating IDs for all students and staff. CMS had to pare its original plan down after Mecklenburg County said it would delay other construction projects. County commissioners still have to give the district the go ahead to use the bond money.