Last week I wrote about some generally helpful hidden iPhone features – but there’s another set of buried settings and features to your iPhone that are also incredible important to learn about: privacy. There are settings and menus within your iPhone’s privacy settings that are 100% undocumented publicly by Apple – the only way to find out what these menu options do is to call into Apple within your first 90 days of tech support.
Below I’ll dive into what these menu items are, how to find them, and most importantly – what changing them will do to your phone, since Apple doesn’t have it anywhere in their documentation. To be clear, I’m not saying you should turn off all settings and lock your phone down – there’s drawbacks to that approach that I’ll throw in at the end. I’ll start off with the most hidden menus, and move onto the more basic privacy settings, in case you’d like a complete guide:
Expert Settings: System Services and Frequent Locations
First, navigate to Settings > Privacy > Location Services > System Services. The only way to learn what these settings mean is to call Apple, which I did. If anyone at Apple ever reads this – it’s a bit shady that you never explain these settings – just a single page explaining them would be nice.
Within System Services, there’s 9 menu items. Here’s what they are, and what privacy you’ll be controlling by toggling them on or off:
Cell Network Search:This tracks cell tower usage and congestion, and sends the data back to Apple for analysis as to what towers are being used the most, how you move between cell towers, and which ones are overused. It does not help your phone locate a cell tower. Turning this off will not affect your phone’s performance, according to Apple.
Compass Calibration:This gives the Compass App the data it needs to function – pretty simple. If you turn this off, your compass stops working.
Diagnostics & Usage:Tracks your behavior, as well as errors, bugs, etc – basic bug fix and product improvement diagnostics. It all gets sent to Apple. Turning this off will not affect your phone’s performance.
Location-Based iAds:Your iPhone will send your location to Apple in order to provide you with geographically relevant ads. Turning this off will mean that you won’t get ads relevant to where you are, or the totally sweet offers that come with it.
Popular Near Me:Locational data about the Apps you use and have purchased will be sent to Apple in order to promote Apps to others in your area. Basically, it’s geotagging Apps for advertisement – turning it off will not affect your phone’s performance.
Setting Time Zone:Your time zone will be instantly adjusted according to your geographic location. Ever notice how as soon as you turn on your phone after a long flight, it displays the local time perfectly, even before getting cell signal? It’s this setting. If you turn it off, you’ll lose that functionality.
Traffic:Monitors your geographic movement and interaction with cell towers in order to understand traffic patterns for the Maps program. This seems to only be used for Apple’s Maps program. However, turning it off will not affect your phone’s performance.
Wi-Fi Networking:This particular setting is interesting, and requires some explanation. As you move around a city, your iPhone is constantly picking up WiFi signals. It geotags that data (“XYZ WiFi is at this GPS location”), encrypts it so that it is anonymous and unique (otherwise the data would look like all hotspots are named “linksys”), and stores it as what Apple calls “crowdsourced Wi-Fi Hotspot locations”. Next time someone walks by that exact hotspot, their iPhone will know where they are without using GPS – because you basically already “marked” the area. Shutting this setting off will stop that info from being sent to Apple. It will not affect your phone’s performance.
Frequent Locations:Stores the frequency with which you visit certain locations, and the time spent in each place. If you go into this menu, you’ll either think it’s really cool, or really creepy: it has a list of your most frequently visited places, and how many times you’ve been there. Turning this off will affect your phone’s features! The iPhone uses this to figure out where you live and work. When you visit your “Today” tab, and it says “With current traffic, it will take you 20 minutes to get to work” – it’s doing this using your frequent locations. Turning this feature off will also disable these functionalities.

Advanced Settings: Location Services
Next, navigate back to Settings > Privacy > Location Services. In simple terms, Location Services is what we’ve come to know as GPS. Apple calls it “Location Services” because they use more than just GPS – they use cell towers, WiFi, and GPS to locate you. For simplicity, just imagine that Location Services provides data that answers the question: “Where are you?”

You are welcome to turn Location Services OFF entirely, but 99% of people enjoy the GPS feature. The better option is to understand and adjust what happens to that locational data.
You probably have a menu that looks something like this image listing a bunch of Apps. The way this privacy setting works is that you’re controlling which apps have access to a single set of locational data.
For example – if you turn off Location Services for Google Maps, you will no longer be located on a map – there’s no locational data to tell Google Maps where you are. Be aware of what apps you’re turning off – you may kill a functionality you enjoy by turning off location data. But, a good rule is this: “If the program never needs to know where I am, I can turn off location data”.
At the bottom of this menu, you’ll see “Find My iPhone” – this is the theft recovery and shutdown part of the iPhone. If you ever lose your phone, this might be a nice feature to have – but it depends heavily on location data.
Basic Settings
Start off by going to Settings > Privacy. On this screen you’ll see a bunch of options, starting with Location Services, which we’ve already covered. Below that, you’ll see Contacts, Calendars, etc – usually ending with Motion Activity.

Think of each of these options as data centers on the iPhone. You have Contacts data, which has your contacts. Motion Activity has data around your physical activity, etc. You can’t stop this data from being collected – it’s a part of how the iPhone works – but these options allow you to change what apps get access to that data.
For example, Google Maps, by default, has access to your microphone data. Why? Frankly, I have no idea – but I don’t use the microphone when I’m using Google Maps, so I turned it off.
Just click through each of these data centers, and select what apps you want to have access.
Next are your social media settings: what apps will have access to your social media stuff. This isn’t as clear an example as above – granting an app access to social media could mean any number of things – it could be creating posts for you, simply gathering data – it’s really tough to tell, and varies on a case-by-case basis. Just be aware of what apps have access to your social accounts.
Last in this section is “Advertising”. According to Apple’s explanation, they use an Advertising Identifier to track your behavior and habits, and give advertisers access to this data to present you with targeted ads. To be clear, your name and personal info is not included in this tracking – your behavior is. So, this section allows you to limit “Ad Tracking”. You will still get the same number of ads, they will just be impersonal – they won’t have that creepy omniscience that knows exactly when you’re craving more peanut butter, etc.
One last thing – if you want to limit ad tracking, you turn this setting ON – it is OFF by default, and OFF is what allows it track you.
Tying Up Loose Ends
If you’ve gone through everything above, you’ve covered 90% of your iPhone’s privacy settings – but there’s a few more places to check. If you just navigate to Settings, you’ll see a list of apps. Each app has its own settings you can toggle – for example, Safari has a “Do Not Track” setting you might want to turn on.
Within each app, from the home screen, you’ll also find there may be a “settings” section with their own privacy settings. For example – from the home screen, open Google Maps. Click the menu tab on the left, and select “Settings”. Then go to About, Terms & Privacy > Terms & Privacy > Location Data Collection. You’ll see here that Google Maps has its own (well buried) privacy setting. I couldn’t possibly list every setting for every app – so just poke around!
Wrap-Up, and Why You Shouldn’t Turn Everything Off
I really hope this guide is helpful, and makes the task of managing your privacy easier – but privacy really is a murky subject. For example, do you enjoy knowing what traffic is before leaving the house? If we all turn off these settings, we won’t have crowdsourced data, which means no more traffic info on Google Maps. If you turn off that “Cell Network Search” setting, you’re cutting off a lot of data that helps build new towers in the best possible locations.
There is a moving line between convenience and privacy – at what point do you want your data hidden, and want to take advantage of crowd-sourced conveniences? My rule of thumb is that if I like the feature, I don’t turn off my part of the data feed. If it’s a bad feature (like Apple’s Maps), I vote with my data. Best of luck with this guide, and please post in the comments if I missed anything.

Thanks a bunch…I appreciate this post.
Is it possible for a family member use certain apps plus some kind of child settings to get some kind of control of my iPhone? It’s it possible for my phone to think it w owned by someone else and be used to hid behind my name phone number FaceTime and somehow take remote control of it. I always find settings on that I turned off all these strange call logs I never made FaceTime call and I never made one call’ I’m thinking something is hacking my phone and advertising somehow through it maybe some kind of dating sites small businesses networking with help from a group. I have been hacked for almost a year and need some kind of help iPhone 6 4135121907
Thx for taking the time to find out what all the features mean under System Services. I’ve been trying to find this information on the Apple website, but to no avail.
This is really helpful however my son has the same iphone as me but he dosent have location services within system services can anyone help with this, thanks
In response to above question, he could have it restricted. Click on settings, general, restrictions, and scroll down to see if location services has been disabled.
Thanks to Clear-Coat Blog for this helpful information.
Would appreciate a post on error messages, the numbers and their meanings. It matters, really. I did a reset on my iphone because I had pages of error messages, and it seemed like the only way to reduce them was to siimply reset it, and yet for me, since I’m relatively new to the iphone, it was not that simple getting everything back on, but it sure helped reduce all the error messages. Sure wish there was a way to simply delete error messages or an app that checks and automatically corrects the errors.
Does the data Apple collects for wi-fi, cell towers, and traffic, for example, count as cellular usage on my limited data plan if I have these services turned on?
thank you very much, this post was very usefull, I turned off some localization settings that were consuming A LOT of data usage, I was afraid of turning this settings off because I had no idea what they were meant for and I couldn’t find any documentation on apple’s documentation.
p.s. Merry Christmas
Very informative article, and answers a lot of questions.
I have a request. Please organize the list in the same order that settings appear in Settings/Privacy/Location Services/System Services. The settings in the order they appear on iOS 8 is:
Cell Network Search
Compass Calibration
Find My iPhone
Location-based Alerts*
Location-based iAds
Motion Calibration*
Setting Timezone
Share My Location
Spotlight Suggestions*
Wi-Fi Networking
Frequent Locations
Diagnostic Usage
Popular Near Me
Routing And Traffic
The ones with an asterisk “*” were never explained. One might assume they are self explanatory…but with corporations (and governments) you never know what kind of surprise is lurking behind a seemingly harmless label. Could you research those with Apple and update the article?
One final thought: turning off “Compass Calibration” won’t make your compass stop working. It just won’t be as accurate (with the setting disabled the compass won’t be able to use your current location on Earth to adjust for magnetic declination).
Thanks again for writing a great article. I look forward to sending an link to everyone I know so they can be better informed.
/Chris
This was great info. A great deal of my concern is about my iPhone battery being used for info. I don’t need. I have changed a few things now and will see if battery life improves.
Thanks for the article. I think you are wrong about the compass calibration though. The compass will work without the location service for it turned on, BUT, if you do have the location service turned on for the compass, underneath, it will also show you your exact GPS location and your elevation above sea level and all that good stuff.
I did this while in the Wal-Mart parking lot with my son the other day with my services off and his on, and the compass worked fine for both of us, but his had some pretty cool information under it that I did not have on my iPhone 4 (I skipped the 5 and went to the iPhone 6 regular).
Thank you very much for this article. I’m like you…I have to know what this stuff does, and Apple should be ashamed for not telling folks what some of these purposefully “sneaky” settings are that come pre-set from the factory.
P.S. After writing this, I see that another guy named Chris has already brought this up, but since I’ve typed it, I’m gonna send it anyway
Thanks again!
Thank you. Very informational. I read this because I’m trying to figure out how someone (I happen to know them too well) is tracking me RV ven though I have “find my phone” off. I appreciate all your information.
I’ve noticed a lot of my data has been used under system settings is this because of this data being sent to Apple ? I have AT&T and an iPhone 6s wondering if you had any idea …..seems unfair to have to be charge for this data