Case #1 · Post Office Horizon Cost of Failure: 700+ Prosecutions

1999. The Post Office deployed Horizon, a new accounting system across its branch network.

By 2015, over 700 sub-postmasters had been prosecuted.

Thousands more accused.

Several died before their convictions were overturned.

The system had bugs. Known bugs.
Bugs that could generate phantom losses with no corresponding cash movement.
Bugs whose existence was not disclosed
in criminal proceedings.