For Googlers that just want to stop the bandwidth usage, do what the OP did and turn off services that may be causing problems:
iCloud
- System Preferences -> iCloud
- Uncheck:
- iCloud Drive
- Photos
Spotlight Suggestions
- System Preferences -> Spotlight
- Uncheck "Spotlight Suggestions"
If you find something else hogging bandwidth on your machine then leave it in the comments and I'll add it here.