AT&T employees took bribes to unlock millions of smartphones, and to install malware and unauthorized hardware on the company's network, the Department of Justice said yesterday...
The bribery scheme lasted from at least April 2012 until September 2017...
The two recruited AT&T employees by approaching them in private via telephone or Facebook messages. Employees who agreed, received lists of IMEI phone codes which they had to unlock for sums of money. more
Remember this survey from 2016? "One in five employees said they would sell their passwords."
The Point: Quarterly Technical Information Security Surveys mitigate this risk, and prove due diligence.