Social media profiles are one of the top things other community users will evaluate you on. On sites like Digg, other users can tell a lot about you, and your intentions, just by what they see in your profile.
How To Create Compelling Social Media Profiles gives a quick overview of what you should consider when building your profile and participating in social media communities.
If you are going to participate in social media then you have to take your profile seriously. Other users will, and they can make their decision to friend you, or avoid you, based on your profile.