In a 2008 civil case concerning insider trading, Buchwald ordered the U.S. Securities and Exchange Commission to unfreeze the ill-gotten profits of Ukrainian resident Oleksandr Dorozhko. Dorozhko was accused of hacking into a company database to access a then-unreleased earnings announcement. Based upon the undisclosed information, Dorozhko invested $41,671 in put options, which he sold the following day for $328,571. The SEC froze the profits, but the judge ruled against the SEC, finding that while Dorozhko's conduct almost certainly was criminal, it did not fall within the relevant civil statute. Buchwald stayed her order pending appeal. The Second Circuit Court of Appeals reversed the judge's ruling. When Dorozhko later stopped participating in his defense, Buchwald granted the SEC summary judgement and ordered Dorozhko to pay nearly $580,000 in disgorgement, prejudgment interest, and a civil penalty. The SEC managed to seize $296,456 of this amount.
''Organic Seed Growers & Trade Ass'n v. Monsanto Co.''
On February 24, 2012, Buchwald dismissed a lawsuit brought by a consortium of U.S. organic farmers and seed dealers aggrieved by Monsanto's genetically modified organism seeds. Monsanto denied that it had harmed anyone. After extensive briefing and oral argument, she held that the plaintiffs had no standing to sue, calling the case a "transparent effort to create a controversy where none exists." The decision was appealed to the Court of Appeals for the Federal Circuit on March 28, 2012. The Supreme Court declined to hear an appeal by the organic farmers in January 2014.
''In re LIBOR-Based Financial Instruments Antitrust Litigation''
In March 2013, Buchwald dismissed much, though not all, of a class-action lawsuit directed at the banks that allegedly manipulated the London Interbank Offered Rate. In a 161-page memorandum of decision, she held that U.S. antitrust law did not apply. She said that since the LIBOR-setting process was never meant to be competitive, the suppression of that process was not anti-competitive. In May 2016, the U. S. Court of Appeals for the Second Circuit reversed the dismissal order, reinstating the lawsuit.
''Knight First Amendment Institute v. Donald J. Trump''
On May 23, 2018, Buchwald held that President Trump's blocking of the plaintiffs from the @realDonaldTrump Twitter account "because of their expressed political views violates the First Amendment." Buchwald differentiated between Twitter's muting and blocking functions, explaining that muting "vindicates the President's right to ignore certain speakers and to selectively amplify the voices of certain others... without restricting the right of the ignored to speak." Buchwald declined, however, to issue an injunction against the President and instead issued a declaratory judgment with the statement that "we must assume that the President and Scavino will remedy the blocking we have held to be unconstitutional." This decision stands in conflict with similar cases from other courts. For example, earlier in 2018, a Kentucky judge upheld a governor's decision to block commenters from his Twitter and Facebook feeds in Morgan v. Bevin. Another example is Florida Democratic gubernatorial candidate Philip Levine, who is fighting a lawsuit for blocking Democratic activist and radio personalityGrant Stern.