Abstract: There are provided a method and a system for detecting and blocking spam activity in a cloud system. The method can be executed at a server. The method comprises receiving from a first user of the plurality of users of the cloud service an indication of a first sharing action for sharing access to the digital object; responsive to the first indication, increment a sharing counter value of a sharing counter dedicated to the digital object; receiving from a second user of the plurality of users of the cloud service an indication of a second sharing action for sharing access to the digital object; responsive to the second indication further incrementing the sharing counter value of the sharing counter dedicated to the digital object; responsive to the sharing counter value reaching a pre-determined threshold value, executing a spam preventive action associated with the digital object.