Hallow has raised over $100 million in venture capital. The app collects prayer habits, meditation frequency, which saints and devotions users engage with, and spiritual wellness data. This creates intimate profiles of users' religious lives — data that in many countries throughout history has been used for persecution. Hallow's privacy policy allows sharing data with third-party analytics and advertising partners.

Prayer requests reveal the most sensitive categories of personal information simultaneously: health conditions (praying for healing), financial distress (praying for provision), relationship crises (praying for marriages), addiction (praying for recovery), legal troubles (praying for justice), mental health (praying for peace), grief (praying for comfort), and fertility (praying for conception). A single prayer request can contain more sensitive personal data than any other app interaction. Pray.com collects this data and, per Mozilla's analysis, does not adequately protect it. The app's advertising-supported model creates a structural conflict: the spiritual content that attracts users generates the intimate data that funds the business. Users submit prayer requests expecting divine confidence. They receive advertising surveillance. In a traditional church, what you say in prayer stays between you and God. On Pray.com, what you type in prayer goes to the database, the advertisers, and the "ministry partners."

Vice's Motherboard investigation (November 2020) revealed that Muslim Pro sold granular location data of its users to X-Mode Social, a data broker that supplied data to US military contractors and intelligence agencies. X-Mode also provided data to the IRS, Customs and Border Protection, and private intelligence firms. Location data from a prayer app reveals mosque attendance patterns, daily prayer routines, Ramadan observance, and -- most fundamentally -- that the user is Muslim. This data was sold to military contractors in a country that had recently implemented a travel ban targeting Muslim-majority countries. Muslim Pro initially denied selling data, then confirmed the X-Mode relationship and stated it had been terminated. The app designed to help 100 million Muslims practice their faith was simultaneously feeding their location data to the US military. The prayer app knew when you prayed. The military knew where.