Oh boy, 15 million identities goes through the window just like that. This really is crazy. All centralized companies with one single entity are dangerous as hell. One breach and there you go. 46 millions in Ashley Madison hack, 15 millions now in T-mobile.
Decentralized definitely is the future and way to go. Sooner everybody realizes that the better!
What does this mean - "all centralized companies with one single entity are dangerous as hell" - this doesn't make sense? All centralized companies, by definition, are single entities...otherwise they'd be a decentralized company.
Further, this has nothing to do with the propensity for data breaches...seriously.
With that said, the use of bitcoin does take some of that information out of transactions but a company like T-Mobile will still need the names and numbers and addresses of their customers and can track the bitcoin addresses used by those people to pay their bill.