Grumman Systems Support Corp. v. Data General Corp.
United States District Court for the Northern District of California
125 F.R.D. 160 (N.D. Cal. 1988)
Data General (DG) (defendant), which owned a copyright in software called ADEX, sued Grumman (plaintiff) for copyright infringement in Massachusetts, alleging Grumman copied ADEX without permission. Grumman separately sued DG for antitrust violations in California state court based on DG's conduct regarding ADEX, and DG removed that case to federal court. In the Massachusetts action, DG sought a preliminary injunction, which Grumman opposed by arguing DG's ADEX-related conduct violated antitrust law - raising overlapping issues with the California suit. DG moved to dismiss or stay the California action as a compulsory counterclaim to the Massachusetts suit.
Whether, under Federal Rule of Civil Procedure 13(a), a second lawsuit whose essential facts substantially overlap with an earlier lawsuit must be treated as a compulsory counterclaim to that earlier action.