Hi5 is a spamming tool sending mails to all your contacts.
Both true and false.
It may happens that you receive a mail from a MSN contact, inviting you to join him on Hi5, allowing you to interact with people around the world.
If you click on the join now button, it will forward a mail to all your MSN contacts, even to those you didn't contact for years.
When subscribing to these types of services its important not to divulge any important information such as passwords or the email address of people you know. This may results in serious spamming problems.
Getting out of Hi5
Go to www.h5.com
Click on Account optionq on the homepage.
On the next page you should have your email address in the middle and down below there is a link Cancel my account and just follow the steps.