Online Buddies, the owner of gay online dating app “Jack’d,” must change its security practices after an investigation by the New York attorney general found the company failed to protect the private photos of its users, including nude pictures.

The app is marketed to men in the LGBTQIA+ community and has approximately 7,000 active users in New York, according to the office of state Attorney General Letitia James.

An investigation found that while the company told users certain photos would be marked “private,” it failed to implement reasonable protections, James announced June 28. The probe began in February 2018, she...