The ability to synch your Messages (as well as numerous other services) across multiple Apple devices is undoubtably a huge convenience, but also one that could lead to a serious breach of privacy. Obviously nobody wants their private messages accessible to friends, family and co-workers. If you are the type to have your text messages arrive on every Mac that you use, you might want to check which ones you are logged into, as you wouldn't want your messages popping up on a Mac that you share with a roommate, or on an iPad that you left at a friend's house.
New features are continually developed for the secure messaging service Signal. The app is knows for its focus on privacy, with end-to-end encryption powered by the open source Signal Protocol. Every message and call is protected from view, except on the intended receiver's device. Android users have had a built-in backup feature for some time.
Contact tracing is an important tool for slowing the spread of COVID-19 infection and has been employed by a number of countries that have had success in curtailing the pandemic. Due to the sheer logistics involved in contact tracing as well as privacy concerns, the concept of app-based contact tracing has recently been gaining favor with research groups. Singapore's health ministry developed and deployed the first such app, TraceTogether, in March.
The data stored on your iPhone is a valuable commodity to both businesses and governments, and if you don't maintain constant vigilance to protect it, it can leak out in any number of ways, including through unscrupulous apps. Aside from tracking your location and purchasing habits among other metrics, apps can also use your iPhone's microphone and camera, potentially allowing them to invade your privacy in the worst possible way - by listening to and watching you. Obviously you want some apps to have access, but there are plenty that don't need it yet ask for it anyway.
Some iPhone owners are tired of the relentless stream of commentary on social media. If Twitter is taking up too much time, or tweets are getting you down, the service provides an easy way to deactivate your account. Accounts that are accidentally or wrongfully deactivated can be restored within 30 days before they are wiped. For anyone ready to throw in the towel on their twitter handle, accounts can be deleted in a few steps.