On Friday, Uber pushed a new 21-page agreement on to all of its 400,000-plus drivers nationwide, forbidding them from filing a lawsuit in the event of a future labor dispute. Drivers were required to agree to the terms on their phones and could not accept any more fares until they did so.

As a result, the lawyer representing California-based Uber drivers in an ongoing class action lawsuit has asked a federal judge in San Francisco to immediately put a stop to the new agreement.

Under Uber's new agreement, drivers are now supposed to only file for arbitration rather than sue or join a class action lawsuit. Unlike the public judicial system, arbitration is wholly private and almost always favors companies over people. Worse still, it makes class action cases nearly impossible, creating a situation where individuals en masse can rarely hold companies accountable for wrongdoing.

A recent investigation into the general arbitration system by The New York Times found that private arbitration is subject to little oversight, rarely can be appealed, does not have clear evidence rules, and is subject to rampant conflict of interest that tilts towards corporations.

Just e-mail optout@uber.com

The document does allow drivers to opt-out of mandatory arbitration within 30 days of agreeing to it, but it does so in a rather oblique fashion.

PLEASE NOTE THAT TO USE THE UBER SERVICES, YOU MUST AGREE TO THE TERMS AND CONDITIONS SET FORTH BELOW. PLEASE REVIEW THE ARBITRATION PROVISION SET FORTH BELOW CAREFULLY, AS IT WILL REQUIRE YOU TO RESOLVE DISPUTES WITH THE COMPANY ON AN INDIVIDUAL BASIS, EXCEPT AS PROVIDED IN SECTION 15.3, THROUGH FINAL AND BINDING ARBITRATION UNLESS YOU CHOOSE TO OPT OUT OF THE ARBITRATION PROVISION.

On the first page of the agreement, it states:

Shannon Liss-Riordan, one of the attorneys spearheading the class action suit known as O’Connor v. Uber, wrote in her Friday filing:

Drivers receiving the agreement would not realize that they are class members in this case, or that by agreeing and failing to opt out of the arbitration agreement, they may be giving up their right to participate. In effect, Uber is trying to substitute its own notice and opt-out mechanism for court-approved notice and supervision of the opt-out process, and has created substantial confusion among class members in the process.

Uber did not immediately respond to Ars’ request for comment late Friday night, but the company told the San Francisco Chronicle that it had informed United States District Judge Edward Chen of its intentions in court on Thursday. Judge Chen then approved them, though Liss-Riordan told the newspaper that she had not been made aware of such approval.

For now, the startup is standing its ground.

“We believe strongly that our agreements are valid, but we are making some changes and clarifications to remove uncertainty for drivers and for us as we work through our multiple appeals on this issue,” an unnamed Uber spokesperson told the Chronicle in a statement.

[UPDATE Saturday 3:33pm ET: Matt Kallman, an Uber spokesman, sent Ars the exact same statement, and declined to answer specific questions as to how many drivers had agreed or opted out of this new agreement.]

Miriam Cherry, a labor law professor at Saint Louis University, told Ars that sending such a new document isn't totally above board.

"Ethically, this is somewhat questionable as they are trying to dodge any ruling Judge Chen would make by sending any new issues to another forum—arbitration," she e-mailed.

Judge Chen will hear lawyers from both sides in court on Thursday, December 17, 2015.