No one likes being subpoenaed. No one. And non-party (i.e., you're not one of the parties named in the case, which means you're neither a plaintiff nor a defendant) subpoenas that are issued in the context of a business litigation or commercial litigation matter can be quite disruptive because the documents that may be sought can be quite voluminous. So when are subpoenas legitimate, and when aren't they legitimate? Or, in legalese, when will the court "quash the subpoena?" The answer is that it depends on which part of New York you're in. "How can that be?", you ask. There's a difference of opinion among the different appellate courts in New York. And while the courts have conceded that there isn't a bright line test to determine the propriety of a non-party subpoena, here are some guidelines that one of New York's appellate courts recently provided: "[T]he party seeking discovery must first satisfy the threshold requirement that the disclosure sought is "material and necessary," whether the request is directed to a party (see CPLR 3101 [a] ) or a nonparty (see CPLR 3101 [a] ). Entitlement to discovery of matter satisfying the threshold requirement is, however, tempered by the trial court's authority to impose, in its discretion, appropriate restrictions on demands which are "unduly burdensome" (Scalone v Phelps Mem. Hosp. Ctr., 184 AD2d 65, 70 ; see Kaye v Kaye, 102 AD2d 682, 691 ) and to prevent abuse by issuing a protective order where the discovery request may cause "unreasonable annoyance, expense, embarrassment, disadvantage, or other prejudice to any person or the courts" (CPLR 3103 [a]). In addition, and particularly when considering whether to enforce a subpoena against a non-party, the courts have considered whether the party issuing the subpoena has shown "that the disclosure sought cannot be obtained from sources other than the non-party." Some examples of this might include where there is a discrepancy or inconsistency in a party's statements, and the discovery sought from the non-party may help clarify the issue. In the final analysis, if you are inclined to fight a subpoena, the decision as to whether you will have to comply with it will be left up to the discretion of a trial judge, and so long as that judge does not exhibit a clear abuse of discretion, an appellate court will not disturb that ruling.