Facebook already requires apps that use the "Login with Facebook" function to ask for your permission to post on your wall, but MyPermissions goes beyond that basic step.
Eavesdrop on the Web
Keeping your eye on multiple sites at the same time is easy enough, but what about the places you don't visit or the networks you don't care to sign up for? How would you know if your name is being bandied about like so much gossip in a small town? You can set up alerts with a fairly new service called Mention, a Google Alerts alternative for social networks.
Set up keyword alerts for your name--or whatever else you want to stay in the loop on--using Mention's iOS and Android apps, website, or Chrome app, and set up filters for the places you want to watch (for example, Facebook and Twitter but not blogs or forums). As with Google Alerts, you can choose the frequency of alerts. Mention seems particularly useful for public figures or companies, and it offers paid tiers for big brands, but it's a good way to monitor your social reputation.
You can stick with Google Alerts, but Mention offers a more pleasant user interface, more in-app context about the alert, stats about the frequency of your mentions, and the ability to interact with an alert--you can respond to a tweet without even leaving Mention, if you wish.
Just say no to geotags
We share photos on social networks without a second thought, but even a harmless photo can contain more information than you want it to. When you post an image, nosy folks can easily glean the location from the photo's geotags, or the information your smartphone attaches to the photos you take.
Researchers at the University of California, Berkeley, and the International Computer Science Institute put together a super-creepy project that shows just how much information you're sharing when you post on Twitter and Instagram--and those results are based just on your geotagged posts, not on the metadata from your photos. If you share enough images from a few places on a regular basis, stalkers can easily figure out where you spend the most time and use that to their advantage.
To avoid telling the world where you'll be on a given day, turn off location services when you post on social networks. You can prevent your smartphone from attaching geotags to your photos by changing the camera's settings.
Of course, if you take your privacy especially seriously, you probably don't want to use a network that gives your information to its advertisers. New social sites and messaging apps are claiming to offer increased privacy in the form of encryption, secret groups, and use of peer-to-peer protocols to prevent tracking by corporate eyes (or the NSA).
Sign up for CIO Asia eNewsletters.