A method for detection of spam in a tagging system can include assigning negative points to each tag in the tagging system responsive to the tag matching at least one spam filter criteria, assigning trust points to a tagger responsive to the tagger's behavior matching at least one tagger filter criteria, wherein the at least one tagger filter criteria depends upon tags assigned by the tagger that are assigned negative points, and restricting a tagging functionality of the tagging system for a tagger if a first predefined threshold of negative trust points is exceeded.