Grinding or other abrasives is the only reliable method. I think I've seen machines that will do this for DIP components. 

A dedicated reverse-engineering person can probably guess the part from the pinout, surrounding circuit, and package or simply have the epoxy removed and look at the identification numbers on the die under a microscope, so it only goes so far. 

In my (somewhat) humble opinion, hiding the numbers on chips is kind of a red flag that the product is really easy to clone, has nothing proprietary in it, and is being sold for a very healthy margin, but perhaps that's just me. You won't find top tier manufacturers doing it. 

You could always incorporate one of these chips. 

Can I remove the labels from ICs?
Quick networking question.  My main dev machine is a notebook and my source control and file server (two computers) are desktops which are not meant to connect to the internet.  My Notebook connects to the internet via wifi - I do not have access to the router otherwise I would plug my servers in via cat5.  

My question is if I purchase a switch and plug all three computers in will my laptop be able to access resources on my two servers, and still be able to access the internet?

I have a spare router and tried connecting all of them that way however my notebook tried to access the internet via that router instead of the wifi connection.  I briefly looked into this however I did not see an option in Windows 7 networking to set a preferred / default connection. 
