The Montgomery County, Tennessee school system is no longer requesting student Social Security numbers. The shift comes months after hackers exposed the personal data of about 4300 current and former students along with the private information of about 4900 current and former employees. In many of those cases, the data included social security numbers. School system spokeswoman Elise Shelton says the school system will generate its own identification numbers for students, using the same system as Clarksville-Montgomery County schools. Shelton says the school system began notifying affected individuals last week by email and has set up a call center to handle questions. A criminal investigation into the security breach is ongoing.