An article in today's Seattle Post-Intelligencer talks about bloggers who are also employed by Microsoft.
Before posting an entry in his personal weblog, Robert Scoble always pauses and considers how he would justify its contents to three people: his boss, his wife and Steve Ballmer.
I have similar concerns and am careful to keep my comments about my job / company to a minimum. I could easily imagine people who aren't aware of blogs getting very concerned that an employee is commenting about their work and attempting to put the kibosh on things.
This happened to me during my post-doc at UMass. The department website was in its fledgling days, and there were links to anyone in the department who also had webpages. I happened to still have a personal page at UPenn with a picture of Eraserhead. Someone one the faculty saw this and grew greatly concerned that the department was "allowing" this kind of oddity. While people generally understand the web, blogs surely make others concerned.
Article found through Technorati's breaking news section.