Howard Adamsky gets it right about so-called "passive candidates". I've been similarly frustrated with the staffing industry's focus on recruiting these folks as well as the insistence that they are somehow "better". They are in fact harder to close and less likely to stay at your company and they require significantly more work to attract. Don't get me wrong, I'm all for cold-calling and networking; just not the push to convert someone who is happy in their current job on a single phone call.
In fact, I'd take it one step further. Passive candidates don't exist. If they are "passive", does the fact that you call them "candidates" convince you that they want to work at your company? Because they aren't candidates, they are leads at best, until you turn them into candidates, at which point, they aren't really passive anymore (I'm sorry, someone who gets on a plane to visit your company is not passive). By calling them candidates at all, we encourage negative recruiter behavior focused on the short term, which can really leave the person on the other end of the phone with a negative impression of the company. I could honestly live out the rest of my life happily if I never heard the term "passive candidate" again.
So you say you don't have the right candidates in your company's resume database? How about marketing to those leads to get them interested in your company so they apply? Maybe we should be talking about "prospects" and not "passive candidates".