> what actually happened with LinkedIn?
It used to be that it would only nag you to sign up or log in when trying to view extended profile attributes. Now it just requires you to log in to even view someone's name and function. It shows up in the search results alright, some day I should find a UA changer to spoof Google and see if they do IP checking or just UA header checking, but generally, they made it completely locked-in now, whereas it was semi-open (at least to view) before. It was a user-configurable setting whether your profile could be viewed by people who are not signed in, and now it's just a completely walled garden.
That's not a microsoft decision per se, my friend who was previously SEO PM at LinkedIn made this change to increase signups.
It does bug me that they pollute search results with login-required resources. Search engines should treat that as abuse, or at the very least default to freely available resources, otherwise they just become a menu without prices.
Google should start delisting their indexes for that reason, just like they are doing for sites with popups.
And even worse MSFT/LinkedIn is suing a small company for spidering LinkedIn's data.