Signs of a Secret Network

One of the more interesting observations of the last couple of days has been the number of emails I am receiving from "recruiting agencies." All state that they have seen my resume online - interestingly it's not posted anywhere public, and responding to one (just to see what would happen) simply resulted in getting more emails from other recruiters.

In '02 a cold call from a recruiter landed me a pretty nice job, so I am not willing to dismiss this entirely, but the sequence of events makes me suspicous.

Never mind that most of the recruiter's web sites look rather amateurish (remember the old FrontPage 2.0-generated sites?).

It's just too weird. Am I being waaay too paranoid, or are these recruiting agencies some sort of scheme or scan?