Now let's say someone just told you this was a kiddie porn site. This is how hacker wars start. Even if they did once display kiddie porn, perhaps they have repented. So this Web site doesn't look like it's there just now. But it could just be the that the machine that runs the disk that holds this Web site is temporarily down.
Ping is a powerful network diagnostic tool.
This example is from BSD Unix. Quarterdeck Internet Suite and many other software packages also offer this wimpy version of the ping command. This can keep the target extremely busy and may be enough to put the computer out of action. If several people do this simultaneously, the target host will almost certainly be unable to maintain its network connection. It's way too easy to be regarded as elite, so don't do it to impress your friends.