Get your Google+ profile in order
Google’s surprisingly popular social network does interesting things with privacy controls. By baking selective sharing right into the network itself, it forces you to stop and think about what you’re sharing every time you post an update. For this, we can thank Google's "circles" conceit: One circle, for instance, can include only family members, while another can be just for coworkers. The bottom line is that you get to define exactly which circles of trust see which particular updates.
It's a clever approach to privacy control, but Google+ still has a few potential issues that are easy to address if you know where to look.
Limit who can find you: First and foremost, remove your Google+ profile from being listed in Google search results. It’s the simplest way to increase your privacy and instantly reduce the number of fake accounts adding you to their circles and spamming your inbox with ads. To keep your profile private, log in to Google+, open Account Settings, and then scroll down to the Profile section and uncheck the box that says Help others discover my profile in search results.
Lock down your profile: Google+ lets you assign individual privacy levels for every piece of data on your profile, but that requires you to dive into the ocean of data that is your Google+ profile. To do so, select the Profile and privacy menu from the left-hand navigation pane, and click the button that says Edit visibility on profile.
Google+ will walk you through the long process of selecting privacy levels for every aspect of your Google+ profile—age, location, education, and so on. It takes a few minutes, but it’s a great way to run through everything you’re sharing online and to determine what to keep public and what to keep private. I prefer to keep most of my Google+ profile private, sharing only with people I have in my circle of friends, but your privacy needs may be different.
Disable photo tagging: Next, scroll down to the Photos section and make sure to uncheck the options to allow Google to display geolocation data with your photos. Also confirm that nobody but your most trusted circles can tag you in their posts. Both features are cool, but they could result in distressing breaches of privacy (when exes tag you in photographs, for example) and even bring snoopers right to your doorstep.
Keep Instagram private
I love Instagram, because all my friends use it to share snapshots of their daily lives. Presumably Facebook loves Instagram for the same reason, since it bought the mobile-focused photo-sharing service for a cool chunk of change last year and is now mining the vast Instagram user base for valuable data.
Go private: Practice safe sharing on Instagram by opening the Instagram app—you can’t do much on the Instagram website except look at pictures—and entering your account settings menu by tapping the blue gear icon in the top-right corner of the profile screen. The most important thing you can do is make your Instagram account private by switching the Photos Are Private option to On. As on Twitter, this setting will keep your Instagram updates from being publicly visible, and will require you to approve new followers before they can see your photos.
Limit automatic sharing on Facebook: Next, open the Share Settings menu and give your social network sharing settings a once-over to confirm that everything meets with your approval. Pay particular attention to your Facebook sharing settings, and consider switching off automatic photo sharing altogether.
If you want to continue posting Instagram photos to Facebook, be sure to set those posts to private automatically by logging in to the Facebook website and navigating to the App Settings menu. From there, find the entry for Instagram and click Edit, and then choose your preferred privacy level from the drop-down menu next to 'Visibility of app and posts'. I like to keep my Instagram photos set to friends-only by default, but your mileage may vary.
Audit your authorized apps: Last but not least, do a quick privacy audit to see which apps have access to your Instagram account. Instagram makes its API publicly available, and lots of great third-party applications out there can access your photos to help you make cards, websites, magnets, and more. But this arrangement also means that those services can pull your images and make them publicly available on image indexers such as Google Images.
If you aren’t using those services for anything, disable their access to your Instagram account by logging in via the Instagram website and accessing the Application Authorization section of your Account Settings page. Here you’ll see a list of every application currently accessing your Instagram account, and you can revoke access on an individual basis by clicking the blue Revoke Access button in the top-right corner of every listing.