One of the reasons why the social networking site Facebook is so popular is because of all the applications and games that users can play and interact with friends.

And among the most popular of Facebook applications is Farmville, a game in which users grow crops and rear livestock on a virtual farm towards virtual agrarian glory.

The game boasts millions of active users, with many logging on during office hours and in school just to harvest cropand take care of the farm so that the virtual produce doesn't wither.

A mother from the United Kingdom saw just how addictive this game can be when she opened her credit card statement to see a £900 bill ($1,914) from charges incurred playing the Facebook game.

It turned out that her 12-year-old son had racked up the charges - purchasing in-game "Farm Coins and Cash" using real plastic. The virtual money can be used to purchase buildings and upgrades within the Farmville game.

According to a report from UK newspaper The Guardian, £288 came from the teen's own savings, while he charged another £625 to his mother's credit card.

The total haul was billed over a roughly two-week period, with the first use of the credit card was on 14 March and the mother, who requested her name not be published, only discovered the charges on 29 March.