Every reasonable employer will google for your name before or after the interview -- this is absolutely clear nowadays. However, if the top results he or she finds are bunch of comments left by the interviewee in communities (I am talking here about the relevant ones, like Hacker News, Stackoverflow, you name it), will this destroy or stronger your reputation?
Does this person looks more like a one who likes chatting about Java, or Python, or Ruby, or VCs, or holywars, or whatever else with other hackers more than delivering the actual result? What do you think?
Why would they want to hire someone who would be gone as soon as their startup took off?