“ Suits for damages on account of these violations plainly are suits for damages under the 'antitrust laws' within the meaning of the enforcement provisions of the Clayton Act. It is only when a violation of § 3 alone is involved that the issue we are concerned with here arises. Yet why allow suits for treble damages for price discrimination under § 2 and not allow them when the discrimination practiced is of the kind condemned by § 3? ”

“ Anyone aggrieved can sue.'
The treble-damage provision of the Clayton Act was written into the law so as to provide incentives for private as well as governmental patrol of the antitrust field. Not a word in the legislative history of the Robinson-Patman Act suggests that this special remedy was to be denied to § 3 actions and granted to those under § 2. The fair intendment seems to have been that § 3 was to be added to the body of 'antitrust laws.' The mechanical device used was an amendment to one section of the Clayton Act. ”

“ In resolving all ambiguities against the grant of vitality to § 3, we forget that the treble-damage technique for law enforcement was designed as an effective, if not the most effective, method of deterring violators of the Act. ”