In the blog post Smartphone Encryption is a Red Herring, I pointed out the folly of requiring an encryption back door for the Good Guys to use. So the question arises- “What can be done? If we don’t want a global encryption back door that can be used by anyone, can we still track the Bad Guys?”
The answer is yes. There are plenty of options that don’t require a global back door. I’m not passing judgment on whether these are inherently good or bad options, just that they are available when there is a reason to track a Bad Guy.