— Social-networking sites such as Facebook can be an effective means of communicating and provide endless hours of entertainment.

People keep up with their friends through such electronic wonders.

Organizations use Facebook, Twitter and other programs to reach out to their members and customers.

You can follow the daily activities of President Obama and his White House guests in the online video diary “West Wing Week.”

A California woman even located her missing children through Facebook, tracking them down in Florida some 15 years after their father had run off with them.

But social-networking sites and Facebook specifically have become the focus of those who want to find out what people are up to – and the information can bring unwanted results.

Numerous universities are now using special software to track inappropriate postings on the Facebook pages of college athletes. Schools say they are under pressure from the NCAA to report such materials – which could include the use of expletives or racial slurs.

UDiligence, a New England software company, calls its monitoring product “reputation management for student-athletes.”

“We’re not big brother, but big mother,” Jamil Northcutt, University of Mississippi assistant athletics director, told The Associated Press.

Northcutt’s school uses UDiligence.

“We’ll get you to just think about it,” he said.

“The more knowledge we can give our kids about this subject, the (better) they’re going to be later on.”

Employers more and more are checking out what employees – and even prospective employees – are posting on their social-networking sites.

The wrong comment or photograph could cost you a job.

The police are expanding their use of Facebook and MySpace.

Officers from across the region attended a seminar last week in State College, where they received instructions on how to use information from social-networking systems to investigate crimes – or to educate users about the dangers of posting per-sonal information and images.

“People are open with the photos they post on their Facebook and MySpace pages,” Punxsutawney police Officer Jeff Winefield told The Tribune-Democrat. “Many people post photos of themselves engaging in activities they should not be doing – for example, underage drinking.”

The bottom line is that while social-networking sites can be fun and useful, they also bring a risk.

The message to all of us:

Before you post a comment or picture on your Facebook page or another site, pause and ask yourself if you can live with the results.

Your reputation could be at stake.