8. The computer program product of claim 7 , wherein identifying the at least one horizontal anomaly comprises performing a spectral clustering method to cluster of the objects across the plurality of information sources.
8. The computer program product of claim 7 , wherein identifying the at least one horizontal anomaly comprises performing a spectral clustering method to cluster of the objects across the plurality of information sources. 9. The computer program product of claim 8 , wherein the spectral clustering method comprises: determining a graph Laplacian of the similarity matrix, where eigenvectors of the graph Laplacian are partitioned into components corresponding to individual ones of the plurality of information sources; determining a distance between the components for each of the objects; and classifying each of the objects into the horizontal anomalies according to the respective distances.