Here's how to hide, secure data on iPhones, iPads and Galaxy devices

Apple got a lot of attention last week when it
released a new privacy policy along with a declaration that
police can't get to your password-protected data.
Essentially, your photos, messages and other documents
are automatically encrypted when you set up a passcode,
with or without a fingerprint ID to unlock the phone. Apple
says it cannot bypass that passcode, even if law
enforcement asks.
Google says it will also encrypt data by default in an
upcoming Android update. The option has been there, but
many people don't know about it or bother to turn it on.
Apple, Google and other tech companies have been trying
to depict themselves as trustworthy stewards of personal
information following revelations that the National
Security Agency (NSA) has been snooping on emails and
other communications as part of an effort to identify
terrorists. Apple is also trying to reassure customers
about its commitment to security and privacy after
hackers broke into online accounts of celebrities who had
personal photos stored on Apple's iCloud service.
Beyond setting up passcodes, some phones have
additional tools for hiding or securing sensitive photos
and documents stored on the phone, particularly if you
need to lend or show your phone to someone.
Here's a closer look at some of those options:
Apple's iPhones and iPads
In the latest software update for mobile devices, iOS 8,
Apple offers an easier way to hide photos from your
collection in the Photos app. Simply press down on the
photo or the thumbnail of it and tap "Hide."
However, the photo will still appear in individual albums,
including a new one called "Hidden." You can go there to
unhide hidden photos.
So why bother? This feature is mainly useful when you
want to let people glance through your entire collection of
photos. That could be when you're sitting with a friend in
the same room or making a presentation before a large
audience. You can hide embarrassing or incriminating
photos such as naked selfies _ as long as you remain in
control of the device. If you hand it to a friend and walk
out, your friend can browse through the albums section.
Samsung's Galaxy devices
The Galaxy S5 phone introduced a private mode. You turn
it on in the settings, under "Private Mode" in the
Personalization section.
You then go through your phone to mark certain content
as private. With photos, for instance, just go to the Gallery
app and select the photos or albums you want to keep
private. Then hit the menu icon for the option to "Move to
Private." This also works with selected video, music,
audio recordings.
After you've marked your files as private, you need to go
back to the settings to turn Private Mode off. Think of that
setting as the door to a vault. Turning it on opens the door
and lets you move stuff in and out. Turning it off closes
and locks the door. It's the opposite of what you might
think: Private Mode needs to be off for your content to be
secure.
Once locked, it is as though the content never existed. No
one will know what's inside the vault, or whether there's
even anything inside. To unlock the vault, you need your
passcode or fingerprint ID.
The private-mode feature is also part of Samsung's
Galaxy Tab S tablets and the upcoming Galaxy Note
phones.
LG G3
LG's flagship phone has a guest mode. You can lend a
phone to a friend without giving your friend access to
everything. You can even set a separate unlock code for
the guest, so that you don't have to give out yours.
Look for "Guest mode" in the settings under the General
tab. You then specify which apps your guest can access.
For instance, you might want to give access to the phone,
alarm clock and music, but you might want to block email
and texts.
In some cases, guests have limited access to your
content. With the Gallery app, your collection of photos
won't generally appear unless they are in the "Guest
album." Guests can take photos, too, and have them
appear there. On the other hand, if you enable access to
the Photos app, your guest gets everything. Likewise,
there are no restrictions with email or texts if you allow
access to those apps.
I recommend logging in as a guest — with the alternative
code — to verify what's available after you pick the apps
to allow.
Beyond the guest mode, the G3 lets you lock certain
images in the Gallery app during normal use, similar to
what the Galaxy devices offer.
The bigger picture
These tips touch only the surface of what you can do to
protect your privacy.
For instance, these apply only to data stored on the
device. For files stored on internet-based storage services
such as iCloud and Dropbox, you'll want to make sure you
have a strong password and turn on a second layer of
protection, often known as two-step verification.
You'll also want to pay attention to what data you're
sharing through apps.
On iPhones with iOS 8, for instance, you can enable a
private browsing mode when surfing the Web using Safari.
Click on the tab view on the lower right corner and hit
"Private."
With iOS, you can also choose which apps can know your
location and when, such as all the time or only when the
app is actively running. Go to the "Location Services"
settings under "Privacy." Unfortunately, it tends to be all
or nothing with Android. You can turn off location services,
but that affects all apps, including maps and others that
might need your location.