“If you give me six lines written by the hand of the most honest of men, I will find something in them which will hang him”
Cardinal Richelieu (1585-1642)
News Corporation is now finding out why they should have had and implemented a good data retention and deletion policy. http://www.theage.com.au/technology/murdochs-new-headache-the-secrets-of-data-pool-3-20120130-1qoq0.html
Some organizations have a packrat mentality when it comes to the retention of data. They keep it all rather than expunging it after it is no longer legally required. That seems like a great idea until clever lawyers start discovery proceedings. Usually those involve "everything you've got" rather than "everything you should legally have". So if you're meant to keep stuff for 7 years, a mechanism should be set up to automatically expunge data that is 7 years and 1 day old.
Many organizations have approached retention laws with an approach of "just keep everything forever to be safe". While that's a noble goal, just remember Cardinal Richelieu's quote.
If you don’t *need* to keep it, you *shouldn’t* keep it on the off chance that you *might* want it.