1. A computer-implemented method for determining whether content contains pornography, the method comprising: receiving the content; generating numerical data derived from characteristics of the content; traversing decision trees using the numerical data for the content to reach leaf nodes of the decision trees, wherein the decision trees are constructed by numerical data generated from previously presented content and human-judged labels for the content, each leaf node having a label describing whether the numerical data corresponds to pornography or not pornography; removing the content if a majority of the leaf nodes return a vote that the content corresponds to pornography; and retraining for detecting inappropriate or appropriate content including: receiving a new plurality of training set images along with new human-judged labels for each new training set image; generating numerical data for each new image of the new plurality of training set images; appending new entries to the matrix using the generated numerical data for each new image of the new plurality of training set images; and adding new trees, branches, and leaves to the decision trees using the new entries from the matrix to determine new patterns in the matrix.