Google & YouTube Connectors
To revoke Qlik Web Connectors access to any of your Google Services, simply browse here, locate the application and click the Revoke button.
Facebook Connectors
To revoke access of Qlik Web Connectors Facebook Connectors, simply browse here, locate the application and remove access.
Dropbox Connector
https://www.dropbox.com/account#security
Twitter Connector
https://twitter.com/settings/applications
Note - in the new web edition of Qlik Web Connectors these should be shown on the About tag of the individual connectors.