A method of processing content units in a distributed computer system comprising a plurality of nodes coupled by at least one communication medium, wherein each of the plurality of nodes comprises at least one independent computer that has hardware processing and storage resources separate from those of any other of the plurality of nodes, wherein each of the independent nodes stores a plurality of content units, wherein the plurality of nodes comprises at least a first node and a second node, and wherein the method comprises the acts of: A) generating (401, 501), on each of the first and second nodes, a list of identifiers of content units stored on that node; B) dividing (403, 503) each of the lists generated in the act A into a plurality of sub-lists, wherein each sub-list includes a particular range of identifiers assigned to a node of the distributed computer system; C) sending (405, 505), from the first node to the second node, the sub-list generated in the act B that includes the range of identifiers that is assigned to the second node and sending (405, 505), from the second node to the first node, the sub-list generated in the act B that includes the range of identifiers that is assigned to the first node; D) receiving, at the first node, the sub-list from the second node and combining the sub-list from the second node with at least one other sub-list generated in the act B to generate a first combined list, and receiving, at the second node, the sub-list from the first node and combining (407, 507) the sub-list from the first node with at least one other sub-list generated in the act B to generate a second combined list different from the first combined list; E) identifying (409, 509), at the first node, whether any content units identified in the first combined list warrant processing and identifying (409, 509), at the second node, whether any content units identified in the second combined list warrant processing; and F) when it is determined in the act E that at least one content unit identified in the first combined list warrants processing: F1) selecting at least one of the plurality of nodes to perform the processing for the at least one content unit identified as warranting processing; and F2) sending (411, 511) at least one instruction, from the first node to the at least one of the plurality of nodes selected in the act F1, to process (105, 413, 513) the at least one content unit identified in the act E as warranting processing. A) generating (401, 501), on each of the first and second nodes, a list of identifiers of content units stored on that node; B) dividing (403, 503) each of the lists generated in the act A into a plurality of sub-lists, wherein each sub-list includes a particular range of identifiers assigned to a node of the distributed computer system; C) sending (405, 505), from the first node to the second node, the sub-list generated in the act B that includes the range of identifiers that is assigned to the second node and sending (405, 505), from the second node to the first node, the sub-list generated in the act B that includes the range of identifiers that is assigned to the first node; D) receiving, at the first node, the sub-list from the second node and combining the sub-list from the second node with at least one other sub-list generated in the act B to generate a first combined list, and receiving, at the second node, the sub-list from the first node and combining (407, 507) the sub-list from the first node with at least one other sub-list generated in the act B to generate a second combined list different from the first combined list; E) identifying (409, 509), at the first node, whether any content units identified in the first combined list warrant processing and identifying (409, 509), at the second node, whether any content units identified in the second combined list warrant processing; and F) when it is determined in the act E that at least one content unit identified in the first combined list warrants processing: F1) selecting at least one of the plurality of nodes to perform the processing for the at least one content unit identified as warranting processing; and F2) sending (411, 511) at least one instruction, from the first node to the at least one of the plurality of nodes selected in the act F1, to process (105, 413, 513) the at least one content unit identified in the act E as warranting processing. F1) selecting at least one of the plurality of nodes to perform the processing for the at least one content unit identified as warranting processing; and F2) sending (411, 511) at least one instruction, from the first node to the at least one of the plurality of nodes selected in the act F1, to process (105, 413, 513) the at least one content unit identified in the act E as warranting processing.