I'm not sure if they have changed it, but when I first looked, they just logged everything from the N2K bus to their server. That was too much data for my data plans, so I never signed up. However I recall talking to them and there was a change coming where you could select what to log to the cloud rather than logging everything. That would be better on data, but you need to know a priori what to log.
I've instead used remote access to the computer running N2KView. I get alarms for various issues, and can check in as needed with remote access.