I'm guessing that none of the people commenting on the original article have ever hired anyone. There's plenty of precedent for this. There are things you aren't allowed to take into consideration when hiring (e.g. sexual orientation, religion, etc) and so as an interviewer, I simply don't ask anything that could result in me knowing. Even social break-the-ice questions like "what did you do at the weekend?" are off limits at interview stage. The reason is to protect myself and the company; if we don't hire a candidate because they lack skills, they can't turn around and sue us on spurious grounds.
So no serious interviewer is looking at FB anyway - it opens up too many potential issues.