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

1. System Preferences -> iCloud
2. Uncheck:
* iCloud Drive
* Photos

# Spotlight Suggestions

1. System Preferences -> Spotlight
2. 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.