When you participate in the social realm - such as a comment on Twitter or updating your Facebook status - Who do you represent? Yourself? Your employer? Both?
I'm always cautious about what I post. Perhaps to a fault. I'll consider all sorts of angles from potential audience to potential misinterpretation. There's no doubt that my contributions in public forum are influenced by my affiliation with EMC. I'm not suggesting this is right or wrong - it's how I'm wired.
Let me give you an example. I'll make it fictitious to cover myself (see, there I go again).