Most institutions (especially financial) have strict document retention policies to protect themselves from situations like this. It's not shady – just a way of limiting liability.

At my first job I made the mistake of discovering a cache of old documents, documents that were far older than the company's seven-year document retention policy. The cache, being my discovery, meant I became the one responsible for destroying it. It was dozens on dozes of bankers boxes filled with documents that I had to de-spine before shredding.

You would have thought that the process was a chore but for me it was exhilarating. The slowness of the process gave me the opportunity to speed read through it all. There was nothing scandalous in there, but I became somewhat of a historian over many quiet nights.