Waymo , the new name for Google’s self-driving car project, has sued Uber and self-driving trucking startup Otto over claims of patent infringement.

In a Medium post published Thursday afternoon, Waymo accused Anthony Levandowski—a former Google engineer now working for Uber—of having downloaded “over 14,000 highly confidential and proprietary design files for Waymo’s various hardware systems.” In particular this allegedly included “Waymo’s LiDAR and circuit board” designs—a total of nearly 10 gigabytes. Levandowski left Google in January 2016, then founded Otto, which was acquired by Uber several months later.

Just last month, Bloomberg reported that Waymo has been able to slash the production costs of LiDAR by 90 percent.

Neither Uber nor Otto immediately responded to requests for comment.

Silicon Valley watchers quickly remarked on Twitter how it was odd that Google, which just a few years ago became an investor in Uber itself, was now turning on the upstart competitor.

@MikeIsaac And its main lawyer, SVP and Chief Legal Officer David Drummond, was on the Uber board for 3 years, just until 6 months ago — Ellen K. Pao (@ekp) February 23, 2017

A months-long gambit

The 28-page lawsuit details how Waymo's suspicions of Levandowski, his company Otto, and Uber, developed quickly in 2015 and 2016, while Waymo began as a Google project back in 2009.

In early 2015, Uber began rapidly moving into the autonomous driving space by recruiting academics from Carnegie Mellon—one of the premier research institutions in the field. By the following year, the civil complaint notes that Uber was still relying on a third-party LiDAR system, while Waymo was continuing to develop its own—"Uber remained more than five years behind in the race to develop vehicle automation technology suitable for the mass market."

As Waymo alleges:

By November 2015, an internet domain name for the new venture had been registered. And by January 2016, Mr. Levandowski had confided in some Waymo colleagues that he planned to “replicate” Waymo’s technology at a Waymo competitor. As Waymo would later learn, Mr. Levandowski went to great lengths to take what he needed to “replicate” Waymo’s technology and then to meet with Uber executives, all while still a Waymo employee.

Whois records show that Ottomotto.com was registered on Google's own registrar system on July 12, 2015.

As Google tells it, Levandowski then conducted his data heist on December 11, 2015, then copied the data to an SD card three days later. The following day, December 18, he reformatted the laptop. Levandowski then met with Uber officials in San Francisco on January 14, 2016, and resigned from Google less than two weeks later. Otto, Levandowski's company, publicly launched in May 2016. Within months, Otto was poaching Waymo engineers, who allegedly also brought internal data and materials with them.

By August 2016, Uber acquired Otto for $680 million, "a remarkable sum for a company with few assets and no marketable product."

Waymo officials began to grow increasingly suspicious of Otto's rapid rise, ultimately discovering his massive download. Those worries were confirmed further at the end of 2016. As the suit continues:

Then, in December 2016, Waymo received evidence suggesting that Otto and Uber were actually using Waymo’s trade secrets and patented LiDAR designs. On December 13, Waymo received an email from one of its LiDAR-component vendors. The email, which a Waymo employee was copied on, was titled OTTO FILES and its recipients included an email alias indicating that the thread was a discussion among members of the vendor’s “Uber” team. Attached to the email was a machine drawing of what purported to be an Otto circuit board (the “Replicated Board”) that bore a striking resemblance to – and shared several unique characteristics with – Waymo’s highly confidential current-generation LiDAR circuit board, the design of which had been downloaded by Mr. Levandowski before his resignation.

The suit also claims that Uber and Otto are liable under the 2016 "Defend Trade Secrets Act," a law that paved the way for such cases.

UPDATE 10:30pm ET: Chelsea Kohler, an Uber spokeswoman, sent Ars this statement by e-mail: "We take the allegations made against Otto and Uber employees seriously and we will review this matter carefully."

She added by text message that there is "no investigation of Anthony at this time."