United States v. H & R Block, Inc.

H&R Block, Inc. (defendant), the leading retail tax-preparation company, sought to acquire 2SS Holdings, Inc. (defendant), owner of the TaxACT line of digital do-it-yourself (DDIY) tax-preparation products, at a time when H&R and 2SS were respectively the second- and third-largest DDIY providers. The United States sued to enjoin the acquisition, arguing it would violate § 7 of the Clayton Act by substantially lessening competition in the DDIY tax-preparation market; H&R argued the relevant product market should be defined more broadly to include all methods of tax preparation, not just DDIY products.