The managing counsel of data privacy for Uber, the app-based ride-sharing company, said in a Friday blog post “approximately 50,000 drivers” were impacted by a security breach identified by the company in late 2014.

Katherine Tassi, Uber’s managing counsel of data privacy, writes that on September 17, 2014, the company discovered that one of its databases could have been breached. An ensuing investigation by Uber revealed “a one-time unauthorized access to an Uber database by a third party had occurred on May 13, 2014,” Tassi’s statement reads.

Name and license plate information of Uber drivers operating in multiple states were contained in the compromised database, according to Tassi’s statement.

Related: Uber sketchy: now your driver could be anybody.

About 10,000 Uber drivers operate in the city of Boston alone, according to a report published January 22, 2015.

Here’s Tassi’s full statement:

In late 2014, we identified a one-time access of an Uber database by an unauthorized third party. A small percentage of current and former Uber driver partner names and driver’s license numbers were contained in the database. Immediately upon discovery we changed the access protocols for the database, removing the possibility of unauthorized access. We are notifying impacted drivers, but we have not received any reports of actual misuse of information as a result of this incident.

Uber takes seriously our responsibility to safeguard personal information, and we are sorry for any inconvenience this incident may cause. In addition, today we filed a lawsuit that will enable us to gather information to help identify and prosecute this unauthorized third party.

Here’s what we know:

  • On September 17, 2014, we discovered that one of our databases could potentially have been accessed by a third party.
  • Upon discovery we immediately changed the access protocols for the database and began an in-depth investigation.
  • Our investigation revealed that a one-time unauthorized access to an Uber database by a third party had occurred on May 13, 2014.
  • Our investigation determined the unauthorized access impacted approximately 50,000 drivers across multiple states, which is a small percentage of current and former Uber driver partners.
  • The files that were accessed contained only the name and driver’s license number of some driver partners.
  • To date, we have not received any reports of actual misuse of any information as a result of this incident, but we are notifying impacted drivers and recommend these individuals monitor their credit reports for fraudulent transactions or accounts.
  • Uber will provide a free one-year membership of Experian’s® ProtectMyID® Alert. If impacted driver partners have questions or need an alternative to enrolling online, please call (877) 297-7780 and provide the Engagement number listed in the notification letter.
  • We have also filed what is referred to as a “John Doe” lawsuit so that we are able to gather information that may lead to confirmation of the identity of the third party.