>data into "cages" or "vaults" agents can't access.

This is likely worse as it turns people into the kind of "3 laws safe" thinking. Reality has shown us there is no such thing as an unbreakable cage (well, maybe a black hole is, but you can't get anything back out of it in a useful time frame).

By the time you realize the cage was flawed your data may already be distributed far and wide.