A lawsuit filed Monday alleges that BART and a Boston-based software developer secretly collected personal information from thousands of passengers anonymously reporting crimes using the agency’s BART Watch mobile app.

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26-story housing highrise eyed in downtown San Jose Albany resident Pamela Moreno is the lead plaintiff in the suit, which seeks unspecified actual and punitive damages against BART and software developer Elerts Corp. The suit alleges that the two compromised the privacy rights of tens of thousands of app users by violating the Cellular Communications Interception Act and the Consumers Legal Remedies Act.

BART encourages its riders and others to use the BART Watch app because of its quick and discreet method for reporting suspicious activity to BART police. The app also promises anonymity.

In a statement Monday, BART said it does not use Elert’s system to randomly track users, and an app’s user location information is only available if users selects an option to share their location information. “For all users, sharing their contact information and location information is optional,” BART spokeswoman Alicia Trost said.

“The safety and privacy of our riders are a priority, and we want to make clear we are not using Elert’s system for any other purpose than responding to security and safety reports made by our riders.”

According to the lawsuit, the programmers of the app designed it to collect any smartphone’s unique numeric cellular identifier (IMEI). The suit alleges the app collected IMEIs and also periodically monitored the users’ locations when they weren’t reporting incidents. It also states the app tracked the identities and locations of those reporting incidents anonymously.

The cellphone users did not consent to those tracking practices and were unaware of them, the lawsuit claims. It also claims the app’s privacy policy remains vague.

In its statement, BART said the user agreement is clear, and the privacy policy can be found in multiple areas, including the BART website on the BART Watch page, the end-user agreement, and the Elerts website

The lawsuit does not request a specific dollar amount in damages, but notes that “the amount of controversy exceeds $5 million.” It also is seeking an order prohibiting BART and Elerts from collecting IMEIs and users’ locations.

Moreno downloaded the app on her Samsung Galaxy S7 in 2016 and used it regularly as part of her commute. The lawsuit alleges she would not have used the app had she known it was collecting her personal information. Moreno was not immediately available for comment.