Is been around for ages and is part of the kernel. NSA has a dual mission of protecting national security information and also collecting intelligence. This w

Is been around for ages and is part of the kernel. NSA has a dual mission of protecting national security information and also collecting intelligence. This was developed as part of the former. It's not like they have direct commit to the kernel or something, the code is reviewed. If they were to inject something sneaky or nefarious, they wouldn't do it in their own name and so publicly.