The owners and developers of the hot new social networking app Down To Lunch have been hit with a class action lawsuit, alleging they illegally used text messages to “spam-vite” potentially thousands of people to download the app.

On April 22, attorney Ari J. Scharg, of the firm of Edelson PC, of Chicago, filed suit in Cook County Circuit Court on behalf of plaintiff Matthew Warciak and a putative class of other plaintiffs against San Francisco-based Nikil Inc., which the complaint said developed and marketed the Down to Lunch smartphone app.

The app, launched in 2015, has through the early months of 2016 steadily increased in popularity among both iPhone and Android smartphone users, according to reports published in such publications as The New York Times and Digital Trends.

The app works by helping friends – particularly, high school and college students – suggest activities to other friends. When they agree on an activity, such as “lunch,” “chill,” or “study,” among others, those wishing to participate click the button labeled “I’m Down.”

The app’s simplicity and appeal helped fuel its rise to the tops of the charts of apps downloaded by iOS users.

However, Warciak’s lawsuit alleged Down To Lunch’s rapid rise was also powered by improper marketing techniques using potential users’ mobile phones.

According to the complaint, Nikil used DTL app users’ contact lists to generate lists of numbers to which to send marketing text messages for the DTL app.

The lawsuit alleged Nikil “programmed the application to automatically send text messages” that used app users’ names to make it appear a friend had “personally invited” those receiving the text messages to download Down To Lunch “so you can both hang out together,” in a technique the complaint said is known as “spam-viting.”

“By accessing data from a user’s contact list, Nikil was able to personalize the text message to include the recipient’s name as well as the names of five other users (that the recipient may know) that purportedly signed up for the Down To Lunch mobile application,” the complaint said.

The text messages also included a link that could directly take those receiving the text messages to the Down To Lunch website or directing iPhone users to the DTL download in the Apple App Store.

The complaint said the app doesn’t allow those using the app whose phone contact information is allegedly used to send the text messages to “modify, review or alter the content of the promotional text message. Instead, Nikil alone has the full control over the content of the messages, the timing of its transmission and the number from which it is sent. Moreover, the Down To Lunch mobile app does not inform or warn the app user that an invitee will be sent a text message, nor does it obtain (or require) an invitee’s consent prior to sending a text message.”

The complaint alleged all text messages were sent by this automated system without obtaining consent from those who received the texts, which the complaint alleged violated federal telecommunications laws. They also alleged the purported actions violated Illinois consumer fraud laws.

The complaint asked the court to order the app’s developers and owners to “disgorge any ill-gotten funds acquired as a result of its unlawful telephone calling practices,” and pay statutory damages, of as much as $1,500 per text message sent.