Clearly you've never done business in China
Different countries have different set of ethics and laws when it comes to protecting IP.
There are some truths to where factories that produce a western product on a contract basis are also producing the knockoffs that flow out a different part of the factory.
So to say that the Chinese will never do that... sorry you're talking out of your arse.
The bigger problem isn't copyright infringement but the laws concerning product injury. The guy who killed himself over the lead paint did so, not because he made copies but that he created a dangerous product that caused harm. The melamine milk scandal, I believe called for a death sentence. So the point is that the penalties are severe.
With respect to Cisco kit being faked, is nothing new. But hey! That's what you get when you outsource and offshore your manufacturing to countries that don't have the same respect for IP and laws protecting IP.
CRN (Computer Reseller News) did an article a couple of years ago. Looking at the kit, I couldn't tell the difference, but I'm not inspecting it, just judging from photos. Back then the manufacturers were the ones printing the labels, boxes, etc ... Looks like China has cracked down so that now they sell the boxes, sans logos and the dupes in the US now are the ones counterfeiting it. (fake labels and manuals).
With respect to implementing back doors, oh yeah, its possible. Very possible. Which is why Cisco should create a version of their products manufactured here in the US which would sell at a premium.
Be afraid, very afraid.