Waymo alleged that Anthony Levandowski, who headed up Waymo/Google's self-driving car division, took confidential intellectual property (roughly 10GB of data files that were downloaded from corporate servers) with him when he left in early 2016 to start Otto. Otto was a self-driving truck company that would end up being purchased by Uber. Alphabet's thinking is that Otto, and more importantly Levandowski, was a huge "get" for Uber thanks to the Waymo/Google IP that Levandowski was able to obtain.
Uber is then alleged to have used that technology to help jumpstart its efforts in self-driving vehicles, which could someday replace its scores of human drivers.
Uber CEO Dara Khosrowshahi took a conciliatory tone when announcing the settlement, writing, "To our friends at Alphabet: we are partners, you are an important investor in Uber, and we share a deep belief in the power of technology to change people’s lives for the better. Of course, we are also competitors.
"And while we won’t agree on everything going forward, we agree that Uber’s acquisition of Otto could and should have been handled differently."
Khosrowshahi goes on to add that while he doesn't believe that Waymo's trade secrets were used in the development of Uber's autonomous vehicle program, the company is "taking steps with Waymo to ensure our Lidar and software represents just our good work."
For its part, Waymo was all business, writing in a statement, "We are committed to working with Uber to make sure that each company develops its own technology. This includes an agreement to ensure that any Waymo confidential information is not being incorporated in Uber Advanced Technologies Group hardware and software.
“We have always believed competition should be fueled by innovation in the labs and on the roads and we look forward to bringing fully self-driving cars to the world.”