Proxy to return a header in your email. CSS to render the content upon click. IFrame to update content so it doesn't get cached.

Cute web hacks. I don't understand the problem with simply using their mobile app if you were really looking for work.

It sounds like an unnecessary feature for people who are looking and an annoyance to people who are not. That seems to be the problem of Linked In. They harass those who are working with vague and misplaced job requests in an attempt to expand their reach.

I also hate iFrames. Cool trick though.