Even if most people don't have the technical chops spy on traffic themselves, I can imagine a world where there are companies that provide such things as products / services. (Probably there are already a few companies like this, I haven't checked.) For example one might be able buy a gizmo with an antenna that listens in on people's wifi and mobile connections. If end to end encryption was banned, I'm guessing that spying on that non-encrypted traffic would take about $50 and an afternoon of setup, and would not require any special skills.
>I'm guessing that spying on that non-encrypted traffic would take about $50 and an afternoon of setup, and would not require any special skills.
I could see it even becoming a feature in consumer grade network equipment. A bit like HDCP circumvention in video capture boxes or region free playback in optical media players. All you'll have to do is shop around.
It's possible that the commission will require ISPs to block non-backdoored TLS. But I'd consider that to be more of a worst-case scenario, rather than something that's particularly likely to happen. More likely outcome is companies that store user messages on their servers won't be allowed to provide end to end encryption, and would be forced to store the messages on their servers in plaintext, or using backdoored encryption. The bill allows for differing requirements for different kinds of services, so hopefully ISPs would not have much of a change from the current situation.
Of course, even just that scenario is bad enough. It would mean that the police, the FBI, the NSA, people at the messaging company, and hackers who breach the company's security would all be able to read those messages.