[onion2k]

I think it does harm you not to have a profile, but only indirectly. Employers will search for you. Having no profile means you're missing out on an opportunity to make an impression before the interview - candidates with posts about things they find interesting in job-related fields, or status updates that make them look like sociable, interesting people, will benefit from that. Having no profile puts you behind those people.

Mind you, having a bad profile will get you rejected, so no profile might be better in some people's cases.

[lkrubner]

"Employers will search for you."

I said this in a separate comment, but I want to read this here, in response to what you said. In the last 10 years, I've never had an employer search for me online. Never.

[aprdm]

How would you even know that?

[onion2k]

I've had several search for me. I know this because they've raised it in interviews, asking things like "The <X> library you tweeted about is interesting. Where would you use that?"

[tedmiston]

Just because they don't tell you that they read your blog posts or searched for your accounts doesn't mean they didn't…

[mdlap]

My last two employers mentioned searching for me online. Or rather, they brought up the results of the search.