[mynewtb]

How can data be retracted from a blockchain?

Both those sites are also subject to laws and can easily retract information if necessary.

[JoshTriplett]

> How can data be retracted from a blockchain?

In much the same way data can be retracted from printed copies of newspapers that already have widely circulated copies in both personal and institutional/library hands: by publishing a subsequent retraction later in the chain, like any other change.

[simonsaidit]

The change and what was previously there is left for anyone to see in the blockchain.