When it comes to electronic preservation of evidence in civil litigation (as opposed to criminal evidence collection), there is some discussion about what is the best evidence to preserve.

On the one hand, you want to ensure you collect everything that is relevant.  On the other, you can’t collect primary sources for everything in most modern companies, because it is too disruptive.  For example, we don’t collect the disks from the email server, but this is highly likely in a criminal proceeding.

The question then becomes, what’s best?  How do you preserve defensibly whilst doing so economically?  Particularly when preservation requirements begin when litigation is a potential and not an actual event.

Our mandate is to preserve broadly, but how without breaking the bank?

By using a reasoned approach, seasoned with the perspective of a potential litigator and a judge.

When collecting materials, consider what might play out and designate accordingly.  Then determine what’s the most effective means of preserving it, and what arguments you can make if you’re excluding anything.

For example, if we preserve email based on a filter, is that filter sensible in terms of what the litigation might reference?  If the filter is too restrictive, opposing counsel will object and the judge might rule in their favor.  If we collect too broadly, we risk exposing client business secrets and increasing expenses for evidence handling.

Whatever the limitations you impose on a potential pool of evidence materials, make sure your rationale is sound.  Put yourself in opposing counsel’s shoes and ask the questions they will ask.  Follow the leads they will see, and document why a direction doesn’t make sense or is overly burdensome.

In the end, it is best to over preserve than under, but there’s no reason to overwhelm a client with a massive collection effort if something smaller makes sense.  Just make sure you can back it up with fair reasoning.