> Vandalism can be reduced by excluding fare evaders because that's a class of people rather than a class of devices.

Just observing: People who don't own an iPhone or modern android are also, generally, of a class -- and probably one banks would prefer to not do business with for profitability reasons.

People who don't have spyware/lockinware for principled reasons are currently rare enough to not matter in this analysis-- though sure, they're probably customers the bank wants.