Passwords are no safeguards Typing your password or credit card number into a computer is a moment's work. But if you think your personal details disappear as soon as you hit the Return key, think again: they can sit on the computer's hard disk for years waiting for a hacker to take them. As people spend more time on the web and hackers become more experienced, the dangers of storing personal information on computers are growing by the day, security experts say. There are some safe-guards, such as never allowing your computer to store your passwords. But even that in no guarantee of security. When you type in a password, it is stored in random access memory (RAM), where it is held temporarily until other data overwrites it or the computer is switched off. But every so often , the computer copies the contents of its RAM onto hard disk, where it is easy to prey  for a hacker, who can read it directly or design a worm to e-mail it back. The longer sensitive data stays in RAM, the more likely it is to be copied onto the disk, where it stays until it is overwritten-which might not happen for years. Tal Garfinkel and colleagues from Stanford University have created a software tool which simulates  the workings of a complete computer system. Within the simulation, sensitive data can be tagged and then tracked as it passes through the system. Next, Garfinkel and his team simulated computers running common software that regularly handles passwords or secret personal information, such as Internet Explorer, the Windows login script and Apache server software. In a paper to be presented, they conclude that the programs took no measures to limit the length of time the information is kept. Some of the tested software even copied the sensitive information, obviously without restraint . What does the passage mainly talk about?
It's important to set passwords to your computer. Passwords help keep your personal information. It's unsafe to store personal information on computers. There are some safeguards for your personal information.