On most social media networks, it seems like anything goes. Things are a little more loose on Facebook and Twitter, but LinkedIn is strictly professional, giving it a different kind of status when it comes to etiquette. You have to be careful about what you put out there, how you make your requests, and remember to be polite.
This graphic illustrates these data as a spatially aware treemap. The size of each block represents the number of tweets emanating from that country and the shading reveals in the number of geocoded tweets as a proportion of that country’s Internet population