20. The computer system of claim 19 , wherein the apparatus further comprises a query-processing mechanism, wherein the query-processing mechanism is configured to: receive a new query; determine whether the new query is related to the specific topic; and to process the new query to produce query results, wherein if the new query is related to the specific topic, processing the new query involves adjusting relevancy scores for documents based on annotations associated with the documents, wherein the annotations indicate whether the documents are related to the specific topic.
21. The computer system of claim 20 , wherein while adjusting the relevancy scores for documents, the query-processing mechanism is configured to: boost relevancy scores for documents which are annotated as being related the specific topic; reduce relevancy scores for documents which are annotated as being spam documents; and to change the rankings of search results based on the adjusted relevancy scores.