Is it possible to allow sideloading and keep users safe?

Summary

In which I attempt to be pragmatic. Are you allowed to run whatever computer program you want on the hardware you own? This is a question where freedom, practicality, and reality all collide into a mess. Google has recently announced that Android users will only be able to install apps which have been digitally signed by developers who have registered their name and other legal details with Google. To many people, this signals the death of "sideloading" - the ability to install apps which don't originate on the official store. I'm a fully paid-up member of the Cory Doctorow fanclub. Back in 2011, he gave a speech called "The Coming War on General Computation". In it, he rails against the idea that our computers could become traitorous; serving the needs of someone other than their owner. Do we want to live in a future where our computers refuse to obey our commands? No! Neither law nor technology should conspire to reduce our freedom to compute. There are, I think, two small cracks in that argument. The first is that a user has no right to run anyone else's code, if the code owner doesn't want to make it available to them. Consider a bank which has an app. When customers are scammed, the bank is often liable. The bank wants to reduce its liability so it says "you can't run our app on a rooted phone". Is that fair? Probably not. Rooting allows a user to fully control and customise their device. But rooting also allows malware to intercept communications, send commands, and perform unwanted actions. I think the bank has the right to say "your machine is too risky - we don't want our code to run on it." The same is true of video games with strong "anti-cheat" protection. It is disruptive to other players - and to the business model - if untrustworthy clients can disrupt the game. Again, it probably isn't fair to ban users who run on permissive software, but it is a rational choice by the manufacturer. And, yet again, I think software authors probably should be able to ...