Recently, I added Google analytics to one of our company website. It is a very easy service to use and gives you valuable information about visitor behavior on your website.
There is a new section in google analytics dashboard called "Real Time", which shows you real time visitor information such as location and pages visited. Our company business is entirely based on in the US, so recently I was baffled to see that there was somebody visiting our website from off the coast of West Africa. Why? Was is from a boat? A hacker on a boat? After a lot of speculation and observation we saw that whenever our visitor from Africa showed up, the city showed up as "zz" when I moused over in on the map and as "(not set)" in pages visited section.
After reading about google analytics we learnt that google cannot always figure out the user location, especially when the visitor is using some browsers like Opera which route requests to their server first. Ok, so "zz" is a some default value which somebody forgot to review I guess. But, why the coast of Africa? Turns out, the location was actually Lat 0, Long 0.