Data Talk: Cache and Transient

E-discovery requests often focus on “tangible” data that exists on physical storage devices, such as e-mail messages, documents, pictures, music, video, sound clips, or application program files. But what about data that is not so tangible, such as elusively cached or transient files that exist only in integrated circuitries such as Random Access Memory (RAM)?  Is that data discoverable? And is there a duty to preserve? Courts appear to say YES, as long as a litigating party has requested it.

In Arista Records LLC v. Inc., 2009 WL 185992 (S.D.N.Y.), several record companies filed a claim for copyright infringement against a Usenet provider, alleging that's subscribers swap music recordings in the format of MP3 files without obtaining permission from the record companies. To prove their case, the plaintiffs requested production of's usage data logs. refused to produce the logs, contending that it had no duty to preserve or produce that data because it is of a transitory nature, and because it serves no business purpose. Arista Records LLC v. Inc., 2009 WL 1851992 (S.D.N.Y.), at *15.

The court was not persuaded by the defendant's argument. Indeed, the court imposed sanctions on grounds that had willfully failed to preserve data that was subject to a discovery request. Noting that the plaintiff record companies had specifically requested the usage data logs, the court held that had notice of its duty to preserve.

In another case, however, the same court distinguishes between e-mails (which have a "semi-permanent existence") and wave forms, or "ephemeral" data displayed on oscilloscope during "tuning" of computer disk drives. The court noted that no business purpose dictated that such data be retained, and held that under a general litigation hold, and absent a preservation order, failure to preserve such data did not warrant sanctions. Convolve, Inc. v. Compaq Computer Corp., 223 F.R.D. 162 (S.D.N.Y. 2004).

In Healthcare Advocates, Inc. v. Harding, Earley, Follner & Frailey, 497 F.Supp.2d 627 (E.D.Pa.2007) a party failed to preserve temporary cache files. There the court held that sanctions were not warranted because the party had not purposefully destroyed cache files that could have been used as evidence.

In reviewing these cases, it appears that the discoverability of cache, transient or ephemeral data hinges on the following factors:

  • whether the data serves a business purpose that warrants retention
  • whether the requested data is relevant to the case
  • whether the party is capable of preserving the data
  • whether data that might have served as evidence has been purposefully destroyed
  • the timeliness of the request for data, and whether a party has been given notice of the duty to preserve
  • whether the party acted in good faith to preserve the data
  • whether the data is inaccessible because of undue burden or cost (FRCP 26(b)(2)(B))

As transient data becomes more important to the discovery process, it will be interesting to see how courts handle situations of cloud computing, where data crosses infinite system domains and geographical boundaries. Stay tuned!