I agree with the general premise, but I think privacy is not the perfect weapon here: if someone is making a public statement (e.g., a personal view expressed on a weblog) they cannot claim that it is a private statement. The goal (I think) is to prevent them being hounded for it outside the channel where it was expressed.

One option is to bring back anonymity so people can make public, anonymous comments. Anonymity has been sharply curtailed (because terrorism) and this is, IMO, bad for society.

Another is to mandate short term limitations on use. For example if the employer wants to look at your online presence they can only look at last week of your posts and only for initial employment consideration. IMO employers should not look there at all, but maybe this may be a palatable compromise.

The chap in HR is not itching to dig dirt on employees -- he just has a distorted notion of due diligence forced on him. If he has a clear, legal definition of what he can and he cannot look into I suspect he will gladly comply. My 2c.