Decentralized identifiers (DIDs) are a new type of identifier that
enables verifiable, decentralized digital identity. A DID refers to any
subject (e.g., a person, organization, thing, data model, abstract entity, etc.)
as determined by the controller of the DID. In contrast to
typical, federated identifiers, DIDs have been designed so that they may
be decoupled from centralized registries, identity providers, and certificate
authorities. Specifically, while other parties might be used to help enable the
discovery of information related to a DID, the design enables the
controller of a DID to prove control over it without requiring permission
from any other party. DIDs are URIs that associate a DID
subject with a DID document allowing trustable interactions
associated with that subject.

This quote is the perfect parody t-shirt to remember the big fail in Parity Wallet multi-sig contract that went on November 6, 2017. Resulting in the loss/lock of nearly $300M worth of Ether (at that