There are plenty of reasons to keep some images on your mobile device private, reasons that have nothing to do with clandestine affairs and flirtatious sexts. Just because you want privacy doesn't mean you're looking to avoid a Petraeus-like scandal.
People have a pretty good grip on securing information on their PCs, but smartphones and tablets are a whole new world for many users, says Miko Matsumura, founder of mobile safety app KeepSafe.
"We're going to see more and more 'oops' or awkward moments over the holiday season because people just don't think when they hand over their tablets to their kids for a game of ' Angry Birds,'" Matsumura told TechNewsDaily.
The biggest problem is automatic syncing, he said. Parents who own compatible smartphones and tablets may forget that when, for instance, they take a picture on their iPhone while gift-shopping, that photo from the store will be automatically uploaded to the cloud and will land in their iPads if they have enabled Apple's iCloud syncing. Oops! Now their kids know what's going to be under the tree on Christmas morning.
Keeping some photos private can be a good thing over the holidays as well. Do you want Aunt Mary to see you doing a keg stand at a party last weekend?
There are numerous "secret folder" apps available in Google Play and the App Store, and most work in a similar way to KeepSafe, which is available for iPhone and Android. You select photos and video that you want to move into your secret folder or vault, then delete the originals from your Camera Roll (iPhone) or Gallery (Android). Your public photos remain available to your friends, family and co-workers, but your private photos are out of sight.
Most of these apps also allow you to take pictures using the in-app camera. Get in the habit of taking photos from within the app, where they will be automatically saved in the vault and not synchronized with any other service. You can always share these photos at any time by emailing them to an individual or by returning them to your main photo roll or gallery.
Extra features, such as a decoy folder, can be helpful if you know there's a snooper in the house. You can have two secret folders, one of them the decoy, with two different passwords . You can hand over your phone with your password to the decoy folder, so that your snoopers will think they're viewing your hidden photos, but the ones you really want to hide will remain secret. Just don't mix up the passwords! Matsumura refers to his app's secret mode as its "James Bond" feature.
My Secret Folder for iPhone and iPad (free with two locks, or 99 cents with eight locks) offers a choice of password formats that could keep you from mixing up your real password and the decoys. You may choose from a standard 4-number password, a pattern-based password that requires you to drag your finger to "connect the dots" to open the app, or a color-sequenced password similar to the old Simon Says electronic game with its green-, red-, yellow- and blue-sectioned ring.
If you're concerned about someone trying to get into your phone when you're not around, try Private Locked Folder, an app that automatically snaps a photo of anyone who tries to unlock your phone with an incorrect password, and that records the date and time of the break-in attempt.
The Android version of KeepSafe has a tricky feature to send photos that "self-destruct" in 10 seconds after they're been viewed by the recipient. (But don't get complacent: It's child's play to take a screenshot in that timeframe: See our review of SnapChat , a picture-based instant messaging app.) It also has a hide feature for text messages.
Matsumura recommends several steps to keep your phone's secrets locked up over the holidays. First, consider turning off auto sync in all of your apps that could land you in trouble, such as Google and Apple iCloud that you've authorized to sync across devices. Likewise, disable auto posting in apps that you've linked to your social media accounts.
[Concerned about email privacy? Read: Beat the FBI: How to Send Anonymous Email Without Getting Caught ]