Security is a double-edged sword. You can use it to protect against others, and others can also use it to protect against you. As computer security becomes stronger, I think it could be almost irresponsible to only mention the "good" uses - hackers accessing your bank account seems to be the cliche example - without also mentioning the malware-hiding, user-hostile, locked-down devices and DRM uses. After seeing what's happened to computing over the years, I'm starting to think that maybe such strong security is not good for society as a whole after all...