In April 2007, I wrote about Plaxo - a service that helps people keep their address books up-to-date.

Now, 18 months later, a reader asks "How do I cancel my Plaxo account?".

Online services usually make it really easy to sign up, but much harder to figure out how to cancel. In Plaxo's case it's not all that difficult if you remember your login ID and password, you can just go to the Help command at the bottom of the Web Link page. You will then see a list of questions, the first one being "How do I delete my Plaxo account?". From there, Plaxo tells you how to cancel.

Your email address is a bit tricky to control, as it maybe in your friend's address book. Your friend may have sent all their emails to Plaxo. So what does Plaxo do with emails in registered users' address books?

The answer is they keep them on secure servers with many operating system features removed so that they are as safe as reasonably possible. They never compare the email addresses across accounts, because that could compromise privacy. They don't sell the mailing lists to other people.

Plaxo never asks for passwords by email, so if you do get an email asking for your Plaxo password, it maybe fake. So don't let anyone have your Plaxo password.

Your friends might want you to have a Plaxo account so they can keep track of your address changes. They may keep inviting you to join. If you want to cease getting Plaxo Invitations, you can Opt-Out by going to Web Link.

Another thing to watch out for is duplicate names. As more people sign up for the Internet, names are more likely to be duplicated. If you want your baby to be anonymous, give it a common name, if you want Google to be able to find it, then give it a unique name.

Plaxo is a company built on trust. They can't afford to lose it. So to those who don't like it, there is a way out.