Technologies are described for suppressing the collection of activity data by an operating system. An operating system provides an application programming interface (“API”) through which applications can submit activity data. The activity data can be exposed to users through a UI that includes UI controls that can be selected to resume previously performed activities. The operating system also provides another UI that includes UI controls for specifying that collection of activity data by the operating system is to be suppressed. When the UI control is selected, the API will discard activity data received from applications. Another selection of the UI control will instruct the API to resume collection and storage of activity data provided by the applications. The UI for suppressing the collection of activity data can also include another UI control which, when selected, will cause activity data previously obtained by the API and stored to be discarded.