s to "enable courts to maintain a 'tighter rein' on the extent of discovery and to minimize the potential cost of tArlide-ranging discovery' ... ." Whittingham v. Amherst Coll., 163 F.R.D. 170, 171-72 (D.Mass.1995) (citation omitted). Accordingly, "[t]he mere fact that many individuals may have discoverabl