There is an issue on posting on the internet. You pick a topic that you believe in or have an opinion on and begin your blog. Do you stop and ponder where that blog is going to go? Or you make a comment on a listserv. Where does that comment go? Does that particular listserv archive or not? Is your comment something that one could find while doing a search on the internet? If you post your views online under your name, you are on record for your comments for a long time if not permanently!
When questioned in court as an expert witness, you need to recall postings that you have done and can be found as THEY WILL BE FOUND! Posting histories can provide a track record that makes a point of view hard to disprove when they cluster in a specific direction. If you are testifying in one direction but have a history of postings on the internet of the other direction your credibility has just been squashed. Consider that when you chat, post and blog.
The internet is a wonderful tool but tools can harm you if you don't take appropriate precautions.