[illvm]

The way blockchain is currently implemented, a distributed ledger for currency necessitates having a chain that grows bigger and bigger. But one could have a distributed ledger which doesn't keep a record since the beginning of time. The ledger could only be valid for, let's say a week, and everything before then is just lopped off. It would still be large, but it wouldn't be gigantic.

[wraithy]

If it's a public blockchain, there's no guarantee that any individual actor isn't just keeping the older data. Same story for a private blockchain.

There might be ways to "remove" data like your parent comment mentioned, but they would probably require making the sharing process a lot more convoluted.