ALBANY – An investigation of 381 Facebook account holders by the Manhattan District Attorney’s Office could threaten the confidentiality of all Facebook users in New York, a lawyer for the company argued Tuesday before the state’s highest court.

Thomas Dupree Jr. told the Court of Appeals that if it determines that Facebook cannot challenge the search warrants issued by District Attorney Cyrus Vance Jr. in a probe of an alleged public pension scam, then the social media company’s ability to resist requests by other prosecutors for unreasonable requests for customers’ data will be crippled.