His letter underscores the lengths that Uber went to in order to get ahead of rivals under its former chief executive, Travis Kalanick, when it prized aggressiveness and the growth of its ride-hailing business above all else. The company is now trying to shift away from that image and stabilize after a year filled with scandals, executive departures and internal battles. Mr. Kalanick stepped down in June, and his successor, Dara Khosrowshahi, has been on an apology tour for Uber’s past behavior.

Mr. Jacobs’s letter is part of a trade secrets case that Uber is fighting against Waymo, the self-driving-automobile business that operates under Google’s parent company. Waymo has said Uber stole information about driverless-car technology from it. Uber has denied Waymo’s allegations, and the case is scheduled to go to trial next month.

Mr. Jacobs’s letter surfaced last month when the United States attorney’s office in Northern California alerted the federal judge in the Uber-Waymo case to its existence. The letter was submitted into evidence because it also detailed allegations that Uber employees potentially conspired to steal trade secrets from Waymo. The judge, William Alsup of Federal District Court in San Francisco, then delayed a trial in the case so Waymo’s lawyers could gather more information on the claims.

At the time, Mr. Jacobs appeared in court about his letter. In his testimony, he walked back some of its claims, including those pertaining to Uber’s alleged theft of Waymo’s trade secrets. Uber had privately settled a lawsuit by Mr. Jacobs for millions of dollars this year.

The document nonetheless paints a picture of Uber’s other competitive tactics, which Mr. Jacobs said had been carried out by Uber’s security team with Mr. Kalanick’s knowledge. At the time, the team was led by Joe Sullivan, the company’s chief security officer.