There’s a hot, new service that the younger crowd is using now that they’ve spurned Facebook. It’s called Snapchat. Facebook reportedly tried to buy Snapchat last fall for something like $3 billion. No deal.

By the way, in case you’re not familiar with Facebook, you might be interested to know that it’s a tool for connecting with old people.” As such, millions of the millennials are leaving Facebook.

Why use Snapchat instead? It seems that the younger generation is finally becoming aware of the downside of over-sharing, at least when done publicly where a parent, a teacher, or a future employer might see it.

Snapchat allows you to send a photo or short video to a friend, but with one special caveat. They can see it for just a few seconds before it goes poof (anywhere from 1 to 10 seconds as specified by the sender). It’s (supposedly) deleted even from Snapchat’s servers. No word about National Security Agency (NSA) servers…

It seems like a great idea right? They’re sending almost 400 million photos per day this way. So why do I say to warn your kids?

I have an iPad Air and iPhone 5S. These Apple products (and the older models too) have a handy, little feature that I use every day. Maybe you do, too. Whenever I’ve got something on the screen that I want to save, say an article from The Wall Street Journal, I press the Power button and the Home button (the round one on the front of the screen) simultaneously… for just a fraction of a second and voilà, it takes a picture of the screen. The article is saved forever in my photo roll.

This very handy function is referred to as a screen snap or screenshot. It also works on Android devices, typically by pressing the Power and Volume-Down buttons together (note: some Android devices work differently). If you’ve never tried it, I bet you’ll find reasons to use it everyday.

The problem is that you can even do a screen snap while viewing a Snapchat. Yes, it requires a little more dexterity because you have to touch and hold the screen to view Snapchat, and then click the other two buttons simultaneously, but it’s not that hard.

Even Snapchat knows this can happen and apparently can’t prevent it. At least the App notifies a sender when an image has been captured. Snapchat co-founder Evan Spiegel warns that the service should not be used for sharing inappropriate images. I’m pretty sure that he’s talking about sexting. Look it up in Wikipedia if you’ve never heard of it. Reportedly, one-third of young adults have done it.

Back to the NSA for a moment. Suppose that you want to share a confidential text, photo, or document with a coworker and don’t want even them (or anyone else) to see it. Maybe you’d like to send it using an “encrypted Snapchat”. There’s actually such a service, now available for both iOS (Apple) and Android (Google) devices. It’s called Wickr.

Unlike Snapchat, Wickr messages are never “in the clear” except when decrypted on end-users’ devices. Further, the messages are never stored on Wicker’s servers. And you can set destruct timers for a much broader range of intervals, up to days if desired, which could be useful for business purposes.

But as with Snapchat, you can still screen snap Wickr content. Wickr chooses not to notify a sender when this happens because it would provide a false sense of security. Indeed, a receiver could always use a separate camera to photograph the screen and absolutely nobody would ever know. As such, you should use this service, or Snapchat for that matter, only with people in your circle of trust.

Bottom line: These are very cool new communication tools but they may provide a false sense of security when sharing text, images, or video. The content isn’t necessarily ephemeral. As with every other form of electronic communication, you should assume that it will exist forever. Like I said, warn your kids.