Danger, Will Robinson! Danger!
Of course, many individuals and companies are prohibited by law from destroying some data. For instance, the US Securities and Exchange Commission has set in place regulations requiring all firms that handle investments to keep all business records for three years. This includes client transactions, monetary records, and emails. Yes, emails. Failure to keep email records has in fact led the SEC to fine some firms millions of dollars.
The Internal Revenue Service recommends that companies and individuals keep tax records for three years after filing a return. The Occupational Safety and Health Administration requires the employers keep some records about the health of employees for 30 years after they leave their jobs. And if you or a client is in the midst of an investigation or a lawsuit, it's always a very bad idea to start shredding records - right, Oliver North? Right, Arthur Andersen?
So I am not suggesting that you start getting rid of everything willy-nilly, in a paroxysm of nihilism. Not only could you very easily cross legal and ethical boundaries, but you may get rid of something important or even vital. However, you should understand that legally, data destruction can benefit you, especially if there is even the hint of a lawsuit. I am certainly not a lawyer, (and if you're not either, you really must consult with a lawyer before putting any policy in place) but it's my understanding that certain standards of law have developed over the years that you need to be aware of, such as:
"If you throw something out or give it away, you have just revoked any legal right to privacy for that object.
If you're sued, and the folks suing you want to look at your computers for deleted files, you have to provide them with access to those computers.
If you're sued and the folks suing you want electronic data, you can't instead provide with stacks of printouts. If they want something in its electronic form, and you have it in electronic form, you'd better give it to them in electronic form.
If you're sued, and you know about the existence of electronic documents, you must reveal information about them.
If you're sued, suddenly instantiating a policy for data destruction will not be seen favourably by the court. No, not at all.
If you're sued, the existence of a haphazard, sloppy policy for data retention and destruction may result in a painful and costly penalty.
If you're sued, the existence of a consistent, reasonable, and enforced policy for data destruction can shield you from legal liability; in other words, you can legally justify a failure to produce documents if you really don't have them and in fact got rid of them according to policy."
Again, I'm not a lawyer. Before doing anything pertaining to destroying data, consult with your organisation's lawyers so that everyone does the right thing.