The issue started about 24 hours ago, where updates were not working, locations of friends were not showing and so on. Here is one user's complaint:
I'm too having problems with latitude. I can't see any of my friends location, and it's not showing my location either. Although my GPS works fine.
Google's Map community manager, Jade Wang said:
There is a bug affecting Latitude. We are working to fix it.
I am not sure how many people use it but there does seem to be a nice amount of complaints that it is offline.
I assume it will be back soon.
Forum discussion at Google Maps Help.
Update: Google posted a new update in the Google Maps Help forums saying:
We recently noticed a bug in Google Maps for Android 6.8 that affected Latitude. We are aware that service was disrupted for some users, and we apologize. We have been working on the situation and have implemented a fix.
To implement the fix, please upgrade to Google Maps for Android 6.8.1. Open the app and tap on the “Join Latitude” icon from the drop-down menu from the top toolbar to sign into Latitude.