Do you really know who your Facebook friends are?

Just as the number of users increase on social media sites, so does the danger.

You might ask yourself, do you really know who your Facebook friends are?

If not, those "friends" could be gathering information about you to potentially harm you.

"Anything you post online can come back to haunt you," said Sgt. Brent Barbee of the Amarillo Police Department. "It can be used through investigations or be viewed by someone you might not necessarily want in your friends list."

Sgt. Barbee said that he did not know of any cases in Amarillo where social media was the reason for a crime.

More and more, burglars can access the information on a person's Facebook page to determine exact times a person is gone from their homes.

"Generally speaking, we recommend that you make as few people aware as possible when you're out of town," he said. "I just tell people to keep their business to themselves. If there's not a lot of need for everyone to know then why tell them?"

Appls like FourSquare, Gowalla and Facebook places are contributing to the danger. Those apps allow users to "check in" to exact locations using GPS technology.

Here are some tips from the site Mashable to help protect yourself: 1. Set your privacy settings to only allow your friends to see your information and content.2. Only add actual real-life friends into your friend list.3. Don't announce you will be out of town.4. Don't post photos of your expensive items.

Along with the physical dangers of Facebook, it is also known to cause an end to marriages.

"One in five divorces, today, Facebook is quoted in the courtroom as being a part of that," said Dr. Leigh Browning, Associate Professor of Mass Communication at West Texas A&M University. "I think it's fundamentally changed how we communicate."

As for some good news, new studies also show that one in five couples meet online.