Removed: nothing. Logging stayed verbose enough to capture authentication payloads “for debugging”.
Outcome: hundreds of millions of passwords were stored in plaintext in internal logging systems.
In 2019, researchers found that Facebook stored hundreds of millions of passwords in plaintext in internal logging systems. This happened because logging was overly verbose and captured authentication payloads “for debugging.”
This is over-engineered observability becoming a security incident.
Source: Meta, keeping passwords secure (21 March 2019)