The Web has been a great job hunting tool, with companies such as Monster.com becoming valuable giants to help with the task. Part of their services includes entering your resume in an electronic format - and a large number of recruiters are likely to call you based on your electronic resume at sites such as these. Many individuals are going further and creating entire electronic portfolios on their personal websites. They would include not only resumes, but links to further details on their work, linked from their resumes.
Electronic portfolios are a great way to maintain information, but it is also a very public forum - which means almost anyone can see your data. Anything published on the Internet is also subject to potential hacking and tampering. If you participate in social networks, someone not liking you could choose to take it out by sabotaging your sites, or creating other ad-hoc site bad mouthing you. Things on the web have a tendency to hang around, and so it becomes important as to how much of yourself you put out for the public to view and review.
It is human nature that when we are in our youth, we tend to be very open about our lifestyles - but in this Web 2.0 highly connected environment, we may not want everyone to know about everything. Potential employers may make snap judgments on habits that you have long left behind. Not every idiosyncrasy that we have is meant for public consumption, and thus it is important to keep these private as well.
Enjoy the increased connectivity and access of Web 2.0 - human beings crave social interaction, so this is very good. However, do not put out anything of yourself that you would not want the world to know, forever.

