Alphabet’s self-driving car unit Waymo is suing Uber and its Otto autonomous trucking subsidiary for stealing the company’s autonomous vehicle sensor technology. Alphabet is also the parent company of Google.

In court documents, Waymo accuses Otto and Uber of taking the company’s intellectual property in order to avoid the risk, time, and expense of independently developing the technology on its own.

Waymo’s case centers around its custom-built Lidar (light detection and ranging) sensor technology. The sensors allow a vehicle to see a 3D picture of the world around it to detect and measure the shape, speed, and movement of obstacles. Not simply accusing Uber and Otto of copying the technology, Waymo’s was given a tip that Otto’s LIDAR design bore a striking resemblance to its own.

In its own investigation, Waymo found evidence that former employee and current Otto co-founder Anthony Levandowski downloaded over 14,000 confidential and proprietary design files for Waymo’s hardware systems, according to a blog post from the company. These files included blueprints, design files and testing documentation totaling 9.7 GB of data.

Waymo accuses Levandowski of using specialized software installed onto his company laptop to achieve this. The company said that after he transferred the information to an external hard drive, he wiped and reformatted his laptop in an attempt to erase evidence.

“We believe these actions were part of a concerted plan to steal Waymo’s trade secrets and intellectual property,” the company stated in its blog post.

Waymo said that it has devoted seven years to research and development for the technology, building up more than 1.5 million miles of self-driving experience on public roads and even more than that in simulations.