There are 2 options:

1) Uninstall the Data Collector

• see FAQ 

2) Deactivate Data Collector

• Login to the account.
• Go to "Admin" --> "Networks"
• Select the magnifying glass on the Data Collector (left side)
• Click on "Deactivate DC" and click om"Unregister DC"

Now the Data Collector will not send data to the account.