We're not talking about hypothetical limits based on the speed of light. We're talking about actual limits based on usage. A plan with a per subscriber usage limit is not unlimited no matter what logic you apply.

I see what you're trying to say, let me say it more clearly for you. "Since Verizon only throttles during congestion it's not a per subscriber limit, it's just network management". First of all, I don't believe for a second that they only throttle during congestion and I also don't believe that the amount of congestion they experienced justifies throttling all the way to 30 kbps. They make the throttling that severe to force people to upgrade plans, not because it's necessary. But all of that is moot because they are still using per-subscriber usage to make their throttling decisions. When two people with the same plan on the same tower are throttled differently based on their usage, that's a de facto usage limit and calling it unlimited is false advertising.

I'm not saying they shouldn't be able to throttle people based on usage. They can do it all day long as long as they don't call it unlimited.