A judge could decide today on Alphabet’s call for an injunction against Uber

Uber and Alphabet will face off in court today over the use of a key piece of self-driving technology. Alphabet wants a judge to order Uber to stop some of its self-driving operations, since it claims Uber stole some of its technology.

A preliminary injunction could mean a lot of things; most notably, Judge William Alsup said it might mean that the head of Uber’s autonomous efforts, Anthony Levandowski, would have to stop any and all work on the technology until the case is decided.

Alphabet is suing Uber for patent infringement, alleging that Levandowski stole 14,000 files before he left Google’s self-driving project to start his own autonomous tech company, which Uber later acquired.

Already, Levandowski has recused himself of all work on lidar — the radar Alphabet is accusing him of stealing — but otherwise he’s continuing in a leadership role as second-in-command.

Uber wanted to depose Alphabet CEO Larry Page and the head of Waymo, its self-driving division, John Krafcik, to try to prove that the company knew that Levandowski took files before he left Alphabet.

That’s because timing is a big part of Uber’s argument against a preliminary injunction.

That sounds backward, but the legal tactic is pretty straightforward. By proving that Alphabet executives were aware of Levandowski’s alleged theft far earlier than they filed the lawsuit, Uber could reasonably prove that Alphabet didn’t see immediate harm. That’s what Alphabet needs to show in order for the judge to grant the injunction.

“Waymo admits it knew in mid-2016 that Mr. Levandowski was leading Uber’s self-driving car project, and that in October it confirmed Mr. Levandowski allegedly downloaded Google files and filed arbitrations against Mr. Levandowski without mention of the supposedly critical downloads,” Uber wrote in a filing dated April 28. “That is, as of October 2016, the alleged download of 14,000 files by Uber’s self– driving car leader was not troubling enough for Waymo to take action.”

But Alphabet previously argued that it didn’t confirm that the documents were stolen until after being inadvertently copied onto an email from a vendor purportedly discussing the design for an Uber lidar.

Uber says Levandowski never worked on the lidar the company’s engineers are currently developing, called Fuji, though Waymo is still alleging that components of it have been copied. However, the companies have now shifted their focus to a lidar called Spider that Levandowski worked on. Uber says it abandoned the development of Spider in October 2016.

“Spider was only a design idea that was abandoned well before this litigation began, never became a completed prototype, exists only as a collection of component parts, and hence cannot infringe any Waymo patent,” Uber’s attorneys argued.

The ride-hail company further claims that its semi-autonomous cars on the road today are using off-the-shelf lidar technology from Velodyne, not the ones Uber’s engineers are developing, so there’s no real risk of harm for Alphabet.

Uber is also arguing that some of the “trade secrets” Alphabet is alleging Levandowski stole are actually “common ideas known to Lidar designers and disclosed in public literature.”

It’s possible that the judge won’t deliver his judgment on whether to grant Alphabet the preliminary injunction at today’s hearing, and he might even send the case to an evidentiary hearing.

We’ll be watching to see whether the judge reveals more details on what exactly the injunction will entail.

Broadly speaking, it means Uber will have to stop using any of the accepted items on a list of trade secrets Alphabet has filed. But Judge Alsup still has to decide which ones count as actual trade secrets, and whether Levandowski’s role at Uber has to be reevaluated for the duration of the case.

This article originally appeared on Recode.net.