xkcd comic strip Security Holes by Randall Munroe. The subjects of the comics themselves vary. Some are statements on life and love (some love strips are random art with poetry), and some are mathematical or scientific in-jokes. Some strips feature simple humor or pop-culture references. Although known for its crudely drawn cast of oddball stick figures, the comic occasionally features landscapes, intricate mathematical patterns such as fractals, or imitations of the style of other cartoonists (as during