Although messaging apps promise secure encryption protocols, there’s always a lingering fear of the potential sharing of data with the authorities. A new collaborative report has revealed what data the Federal Bureau of Investigation (FBI) could legally get from some of the popular messaging apps.

The revelation comes from an FBI document accessed by Rolling Stone and Property of the People (via). The document tells us that apps like iMessage and WhatsApp can provide the most information to the agency provided there’s a warrant or subpoena. The document also names other messaging apps such as Line, Signal, Telegram, Threema, Viber, WeChat, and Wickr.

Thankfully, apps like Signal, Telegram, Threema, Viber, WeChat, and Wickr don’t disclose any message-related information. Meanwhile, iMessage, Line, and WhatsApp offer “limited” message contents to the FBI upon legal request.

A subpoena compels WhatsApp to provide basic subscriber records. But a search warrant will bring up address book contacts and WhatsApp users who have the target individual on their contacts. With an FBI surveillance request, WhatsApp can provide information on the sender and recipient of texts in 15-minute intervals. However, this won’t include message content.

Signal and Telegram don’t share as much information as WhatsApp and iMessage

Message content can be provided to the FBI if the individual uses iCloud backup for WhatsApp messages. This is because Apple has to hand over the iCloud encryption key upon receiving a search warrant.

With iMessage, the FBI gains access to basic subscriber information using a subpoena. Moreover, a court order can provide the agency with up to 25 days of iMessage search queries. If the authorities send in a search warrant, they can make backups of the target device and also view the messages if the individual is using iCloud for iMessage backups. However, Apple doesn’t seem to have a surveillance request arrangement with the FBI, unlike WhatsApp.

Unsurprisingly, apps like Signal and Telegram are more careful about what data is shared with the FBI. Telegram could offer phone numbers and IP addresses during “confirmed” terrorist investigations. Signal can provide the time/date of user registration and the last date the individual accessed the platform.

This document was created jointly by the FBI’s Science and Technology Branch and the Operational Technology Division.