The Clipper Chip[1] immediately comes to mind as the most publicized case of the NSA wanting a backdoor in consumer products. There are also recent stories of the US Government wanting similar encryption disabling mechanisms in other technology[2]. Coupled with the Patriot Act and it letting the NSA eavesdrop on communications, it gives a precedent. A quote I am reminded of is "If you are on the internet, you aren't being paranoid enough".