I can't begin to tell you how often I see attorneys demanding that the other side produce items that don't exist.
CPLR § 3126 Penalties for refusal to comply with order or to disclose
Gottfried v Maizel, 2009 NY Slip Op 09619 (App. Div., 2nd, 2009)
Under the circumstances of this case, the Supreme Court did not improvidently exercise its discretion in only partially granting the plaintiff's motion to compel disclosure. The defendant could not be compelled to produce records, documents, or information that were not in his possession, or did not exist (see Argo v Queens Surface Corp., 58 AD3d 656; Maffai v County of Suffolk, 36 AD3d 765; Sagiv v Gamache, 26 AD3d 368, 369), or that were privileged (see Logue v Velez, 92 NY2d 13). Contrary to the plaintiff's arguments, the Preliminary Conference Order dated February 13, 2008, did not preclude the court from reviewing the propriety of his discovery demands or the adequacy of the defendant's response to those demands.
The bold is mine.