A more common, but less dangerous, problem is ‘spam’, or unwanted advertising. When it first appeared, nobody worried about it, but now it is out of control: more than 50% of all email messages in the world are junk mail, or spam. Unfortunately, some people are now using spam to trick and get money from them. This is called ‘phishing’. The simples trick is to send an email promising that you will get rich. However, to get this money, you must first send your bank details. Of course, they take the money from your bank and don’t get rich!