Alter Ego Required?

If you are an avid blogger, you might find a point in time where you need to separate your work blogging from your personal blogging. Or do you feel that blogging on college time is even proper?

In addition to maintaining this blog I host one for our division and one for our college's participation in the We are IT initiative. I use the same profile on each as they are somewhat related in my eyes. I also enjoy blogging on outside interests such as NASCAR and politics and do that under separate cover. My thought is that I'm not hiding who I am, but I don't necessarily want a straight line connecting the dots. Topics like religion, politics, etc, can be divisive and potentially hurt your business in some ways.

What do you think? Does it matter? Do you have separate persona's online?