One of the tough things about defending class actions is the fact that discovery is asymmetrical. Some plaintiffs use the fact that corporate defendants generate huge numbers of documents to inflict significant costs on the defense by serving large numbers of marginal relevance to any class claims.

So, when plaintiffs withhold actually relevant information, that tends to add insult to injury.

That's what happened in Barnes v. Equinox Group, 2012 U.S. Dist. LEXIS 82688 (N.D. Cal. 2012). During the discovery phase of Barnes, the defendant took nine depositions: those of the two named plaintiffs, the plaintiffs' expert, and six declarants that the plaintiffs had identified. (As most federal litigators are aware, each side in a lawsuit is limited to ten depositions by FRCP 30.)

When the plaintiffs filed their motion for class certification, they added 20 declarants that they had not previously disclosed to be witnesses in the case. (Most of the declarants were also represented by class counsel.) The plaintiffs opposed any further depositions, so the defendant moved for leave to take further depositions.

The court began by recognizing that

putative class action matters can be sufficiently complex to warrant more than ten depositions.

The plaintiffs argued that further depositions were unnecessary because the defendant had already taken several depositions, and because it could rely on information in its own possession. The court did not accept those arguments:

As a threshold matter, the court finds that by relying on these declarants, Barnes effectively concedes that their testimony is relevant to its Motion for Class Certification. Thus, the court will address each of the Rule 26(B)(2) factors in turn. First, the court finds that additional depositions are not unreasonably cumulative or duplicative. To be sure, deposing nine more declarants is likely to be somewhat duplicative and cumulative. The court does not, however, consider Equinox's request to be unreasonably so because Barnes decided that such a large number of declarations were sufficiently important to submit in support of his Motion for Class Certification.

(Emphases in original.)  So, what can defense counsel take from this opinion? Make sure you assert your discovery rights. Where the plaintiff tries surprise declarants, the court will likely let you take the depositions you need.  More importantly, if the plaintiff makes a witness relevant by relying on them, that makes the witness relevant to the case.