Wiretapping Linux?

[Marc Perkel <marc@perkel.com>]

As most of you know the United States is tapping you telephone calls and 
tracking every call you make. The next logical step is to start tapping 
your computer implanting spyware into operating systems. Since Windows 
and OS-X are proprietary this can be done more easilly with the 
cooperation of Microsoft and Apple.

So what about Linux? With thousands of people working on the Kernel if 
someone from the NSA wanted to slip a back door into the Kernel, could 
the do that? I know it's open source and it could be found if anyone 
looks but is anyone looking? Is this something that would get noticed if 
someone tried to do it? I'd like to think it would, but I'm going to ask 
anyway just to make sure.

Conversely, if Microsoft or Apple cooperated with the US government 
could they implant sptware without packets or hidden files being noticed?

I'm in the process of writing some articles about it and want to raise 
the issue of US government implanted spyware everywhere. I know some 
people might think this a little off topic but I'd rather be safe than 
sorry. Who better to ask this question of than those who develop the kernel?

Thanks in advance.