According to a Pew Internet & American Life Project report, almost 25% of all teens between 14 to 17 years old had smartphones in 2012. Those numbers have surely increased since then.

Many parents have no idea just how dangerous smartphones can be to the safety of their teens. They use them to “check-in” all over town, letting strangers know where they are at any given time. Oftentimes, they will text and drive, taking chances with their lives and others on the road.

And, these dangers are just the tip of the iceberg. So, before you allow your child to have a smartphone, you need to establish some important ground rules first.

4 Tips for Keeping Teens with Smartphones Safe

1) No Check-Ins Allowed

Foursquare and Facebook check-ins may seem cool. But, for teens, they can be ways for predators to keep tabs on your kids’ locations. Yes, it may be reasonable for your child to want you, their other family and friends to know they’re at a local hangout, basketball game or concert. But, is this really information you want strangers knowing too?

It’s important that your child’s Facebook privacy settings restrict who’s allowed to see this information. This helps protect them from stalkers and predators. However, when it comes foursquare and similar apps, they’re often Twitter co-mingled. That means that just about anyone “following” the can discover their whereabouts.

So, what’s the answer? Explain to your kids how dangerous these check-ins can be for both them and their loved ones. Then, insist that they never use them to share their location beyond a restricted network of real friends and family.

2) Stop Them from Texting While Driving

Even though talking or texting while driving is illegal in many US states, teens (and adults) still do it. Currently, the number one cause of teen deaths is car crashes. So, the dangers of using cell phone while behind the wheel are undeniable. Therefore, as a parent, it’s your duty to make texting while driving impossible.

Major cell phone carriers have GPS technology that eliminates texting abilities whenever they’re moving at certain speeds. These subscription-based options, such as tXtBlocker, can actually help to save lives. Other options, like DriveSafe.ly, reads emails and text messages out loud to avoid distractions while driving.

3) Second Lines are Safer than Prepaid Phones

Prepaid phones are a common choice for parents hoping to save money on teen cell phone charges. But, they don’t come with the effective parental controls that come with those of major carriers. Therefore, when it comes to safe smartphone use, getting a second line is a better choice.

Second lines from major carriers provide optional location-tracking services. They also provide the text-blocking services mentioned above. Lastly, they also allow you to set limits on the amount of texting and talking they can do each month.

4) Encourage Wi-Fi Use for Apps, Games and Video

One way to keep the cost of data-usage fees down is to use Wi-Fi whenever possible. Have your kids log onto Wi-Fi when downloading videos and apps, or when playing multi-player online games on their smartphones. Make this a habit when they’re at home especially, since you’re probably already paying for Wi-Fi there. That way, they’re not using up those limited GBs of data your carrier gives you per month.