My tin-foil-hat conspiracy theory is that ISPs switch peoples' Internet off intermittently to see if anyone notices and save on bandwidth. And they only switch it back on when you call in to tech support.
The number of times I've had Internet issues, restarted my modem and router and have it not fix the problem, but when I restart them when I'm on the phone with tech support and it magically fixes the problem just makes me so damn suspicious...
Security can mean security against hackers, but it can also mean security against revealing classified information. Classified information about weapons systems (e.g. performance characteristics) is inherently embedded into the code running on those systems, and therefore shouldn't be open sourced.
Source: used to write classified code