1. A method of identifying inappropriate text content in images, the method to be performed using a computer and comprising: selecting an expression from a listing of expressions; extracting an image from a message; using the selected expression as a reference, finding a section of the image that corresponds to a start point and an end point of the selected expression; comparing the section of the image to the selected expression to determine how well the section of the image matches the selected expression; and determining if the selected expression is present in the section of the image based on the comparison of the image to the selected expression; wherein comparing the section of the image to the selected expression comprises assigning, to pixel blocks between the start point and the end point of the section of the image, probabilities of being characters of the selected expression, and further comprising deeming the message as spam based on presence of the selected expression in the section of the image.