Uh, truncation is a huge no-no for security. But, that isn't what I was talking about. For deduplication/hash key/etc kinds of functions where a checksum works (or some other algorithm with a high chance of collisions is implemented for unit testing to assure collision paths are handled correctly).
This is part of the entire discussion, it's possible to use algorithms originally intended for cryptographically secure purposes in places where the reversibility/collision properties aren't considered problems. And likely this will only happen more frequently as algorithms are picked because they have hardware acceleration and are fast rather for the underlying security properties.
BTW: There is a fun game that I've played; see how much you can truncate a modern cryptographic hash before it becomes trivial to find collisions.
