I am not indicating that I have knowledge of the what Linkedin is doing, I am simply using them as an example. Linkedin has become very popular as a social media site for business professional and it is huge. I could easily see Linkedin or some other company create a linkedin-like app that could be made industry specific, sort of like the social media network that was created just for government employees. Does anyone else agree or have a different opinion?

Though I have not seen an app for this, I have seen other professional social media sites trying to be exclusive based on industries. You know what happened to them? They are not around nor did these companies achieve the status of LinkedIn. Actually, I was an early adopter of LinkedIn eons ago when the majority of professionals on LinkedIn were from the technology community. So you can send Linkedin created a site (or an app if you call it that way eons ago) for technology professionals and it just grew and grew and grew.
Also, think of it, with the status of our economy, so many professionals are changing jobs or careers. So an exclusive app may exclude these type of switchers.

OK, then how about a social media site that is more occupation focused. Sort of what Linkedin was in the beginning but remaining that way? I ask because there are some occupation-specific groups on Linkedin that have grown so big that some have already branched off to their own independent site. I belong to one called Social Media Mafia that just moved the group to its own site with its own community.