Sensitive information stored in contracts
Data in the blockchain is public and everyone can see it.  

It is "secure" in the sense that it is computationally very difficult to modify the data later, without making it obvious that you have done so.  It is also unlikely to be deleted, since a large number of computers store the entire blockchain.

The hashing provides a certificate that a large amount of computation was done using this particular data.  Someone who wants to claim that they have the authentic data would have to do even more computation.  But the hashing does not encrypt the data in any way; the data itself remains perfectly readable (in fact, this is essential to being able to verify it).

So such data is "secure" against tampering or loss, but not against being read.