How can it be a scam?
Unless T-Mobile are quietly laundering most of back to them?
I have no idea though why they agreed such a daft penalty.
I wonder what T-mobile / Deutsche Telekom will do with it? You could almost do FTTH for small country like Ireland with that and have enough left for Urban /Suburban LTE for 80% of Irish Population.
Or do 1/2 of Brooklyn.