You cannot catch computer viruses from visiting most Web sites, reading email, chatting, or posting on newsgroups. You can only catch viruses when you open applications or documents that you've downloaded from the Internet. If someone you don't know sends you an email with an attached file, you should check the file with an anti-virus program. This is a very remote possibility, but if you're worried about viruses, you may want to turn off your browser's Java, JavaScript, and ActiveX capabilities.
Security is currently a big issue on the Internet.
You can learn how to protect yourself against viruses, F-Secure Computer Virus Info Center , online fraud National Fraud Information Center , and spam Spam Abuse . You must be very careful when sending messages through the Internet. Shopping on the Web can be an enjoyable pastime, and most online stores are as safe as if not safer than physical stores. However, you must be careful to avoid security lapses when shopping online. Before you purchase something online, make sure that the site will encrypt, or encode your credit card number.