Uber’s tumultuous 2017 came to a close when a former employee wrote a letter saying the company’s Threat Operations Unit developed to help the company achieve its business goals “through illegal conduct even though equally aggressive legal means were available to achieve the same end.”

The letter from Richard Jacobs raises allegations of wiretapping, hacking and bribery, and alleges CIA-trained spies carried out the work.

Uber is currently engaged in a $1.9 billion battle with Waymo over self-driving technology. Waymo, owned by Google parent Alphabet, accused a former Uber employee of illegally obtaining 14,000 confidential documents, then used to enhance similar technology by Uber.

Uber CEO Dara Khosrowshahi wrote, “With regard to the allegations outlined in [Richard] Jacobs’ letter, I can tell you that we have not been able to substantiate every one of his claims, including any related to Waymo. But I will also say that there is more than enough there to merit serious concern.”

The letter became public in a 19-page opinion related to the court proceedings. This is just the latest in a string of scandals for Uber.