In the case of Pinkerton v. Ledoux, the Supreme Court of the United States ruled that a private detective agency could not be held liable for the actions of its agents. The case arose when a private detective agency, Pinkerton, was hired by a railroad company to investigate a theft. The detective agency hired an agent, Ledoux, to investigate the theft. Ledoux was able to identify the thief and the railroad company sued the thief for the stolen property. The thief then sued Pinkerton for damages, claiming that Ledoux had acted beyond the scope of his authority. The Supreme Court held that Pinkerton could not be held liable for the actions of its agents. The Court reasoned that Pinkerton had no control over the actions of its agents and that the agents were acting as independent contractors. The Court also noted that Pinkerton had no control over the manner in which the investigation was conducted and that the railroad company had hired the agency to investigate the theft. The Court's ruling in Pinkerton v. Ledoux established that private detective agencies are not liable for the actions of their agents. This ruling has been cited in numerous cases since then and has become an important precedent in the law of agency.

In the Supreme Court case of Pinkerton v. Ledoux, Justice Scalia wrote a dissenting opinion in which he argued that the court’s majority decision was wrongfully decided and should be overturned. He believed that Congress had not intended to create an implied private right of action for violations of Section 10(b) when it passed the Securities Exchange Act, as this would have been contrary to its purpose in passing the act. Furthermore, he argued that allowing such an implied cause of action would lead to unforeseen consequences and open up potential liability for innocent parties who were unaware they were violating any law or regulation. He also noted that there was no evidence presented at trial showing actual reliance on misrepresentations by investors or other third-party beneficiaries; thus, making it difficult to prove damages under these circumstances. In conclusion, Justice Scalia concluded his dissent by stating “I respectfully dissent from today’s holding because I believe Congress did not intend §10(b) to give rise to a private right of action…and because I am concerned about unintended consequences."