Guard Your Personal Information

You wouldn't give out your e-mail address or telephone number to a stranger you met in the street or at a concert, so why give it out to someone you have met via the Internet? Remember that if you give out information in a chatroom, everyone in that chatroom can see it - not just those you want to see it.
If the wrong people get hold of your mobile number you could find yourself receiving unpleasant or threatening text messages, or even being attacked by a mobile phone viruses. In the worst cases, you may be forced to change your mobile number, which can be a major nuisance for both you and your real friends.
Similarly, giving out your email address too freely can lead to unwanted spam or other undesirable e-mail. If you feel you have to give out your e-mail address online, it's a good idea to use a disposable e-mail address, such as a Hotmail or Yahoo address, and keep your real e-mail address secret. That way, if anything unpleasant happens, you can simply stop using the affected address and sign up for another one.
If you do start to receive abusive texts or emails, let your parents or a teacher know. Telephone companies can often trace the source of text messages and Internet Service Providers (ISPs) may be able to trace the senders of e-mails. Your e-mail program may also allow you to block e-mail messages from specified addresses, or even restrict the messages you can receive to messages from friends already in your address book.