This macOS Hosts chapter might need some improvements. ticket
In a fashion similar to Windows platforms, Apple operating systems also pose many security and privacy threats.
Table: macOS Threats 
- Files on devices can be deleted if they were downloaded from sources competing with Apple companies.
- Intentional backdoors allow remote root privileges, wipes and deletion of applications.
- An insecure design allows execution of malicious code by applications and the extraction of messaging history.
- Devices are bricked if fixed by an "unauthorized" repair shop.
- Devices are bricked that were unlocked without permission.
- Biometric markers like fingerprints are used for device authorization.
- Extensive personal information is sent to Apple servers, such as:
- Automatic uploads of photos and videos used by certain applications; and
- Unsaved documents and program files (without permission).
- Search terms and location information are sent to Apple.
- System files are scanned.
- OSX phones home with info about the Date, Time, Computer, ISP, City, State and Application Hash when any program is executed, by default.  
|User Control and Freedoms
- Allowable programs like media, political, bitcoin and health-focused applications, and games are censored.
- Arbitrary limits are imposed on the use of software.
- Digital restrictions mechanisms are imposed.
- System upgrades are forced without consent.
- Older versions of operating systems cannot be installed.
- It is impossible to manually fix system security bugs that Apple have not addressed.
- User interfaces are designed to make specific options hard to find and enable/disable.
See this write-up by the FSF for further detailed information. 
In public talks, ex-Tor developer Jacob Appelbaum who had access to the Snowden files, hinted that Apple devices in particular were easy to infiltrate by the Intelligence Community.
Unfinished: This wiki is a work in progress. Please do not report broken links until this notice is removed, use Search Engines First and contribute improving this wiki.