most virus's and worms are caused by the end user downloading and running what they shouldn't. The only way to stop that is to not allow those users to have internet access.
if you want to "hide" your IP, the only way is to bounce your data off of another server aka proxy.
You can't do it any other way because an IP is REQUIRED for data to get back to you, unless you believe in fairies, unicorns, and magical routing.
On the other hand, trying to hide from the government by using a proxy means you're passing all your data through someone you don't know. They could easily be spying on your data and it is the perfect way to man-in-the-middle a connection. This means they could fake an SSL session. Since the proxy would be seeing all the data, it could eves drop on an SSL/HTTPS connection and you'd never know.