[Reef]

Is there a law which specifies which advantage is fair and what is not?

Why should any company be forbidden from utilizing assets their employees legally developed, especially when they want to use that asset in pursuit of a key objective ("hire more smart people")? Should a large newspaper be forbidden from advertising their openings in the printed newspaper itself just because other newspapers failed to acquire comparable audience?

[3pt14159]

You'd have to argue that it is a perpetual monopoly due to the advantage - which I'd say is unlikely.

[jcfrei]

Lawsuits are sometimes filed for competitive rather than legal reasons. I just feel like Google could cause a huge disruption for traditional employment agencies. I mean if this helps in finding future Google employees then this could work for almost any tech company. Imagine finding an employee for a very specific machine learning project: You could just filter all persons which searched for a certain paper. That also puts Google+ into perspective - you get a better chance at actually identifying that person.

[danielweber]

The legal question is if there is a disparate impact.

On a personal level, I really don't like "we hire Python devs if you search on Google for python topics," but that's separate from saying there is a legal challenge here.