xkcd is a webcomic created in 2005 by American author Randall Munroe. Describing itself as "a webcomic of romance, sarcasm, math, and language", its subjects include statements on life and love as well as mathematical, programming, and scientific in-jokes. Although it has a cast of stick figures, the comic occasionally features landscapes, graphs, and intricate mathematical patterns such as fractals. New cartoons are added three times a week, on Mondays, Wednesdays, and Fridays.
This picture is an xkcd cartoon titled Wikipedian Protester, one of several references to Wikipedia which have appeared in the comic.Image: Randall Munroe (xkcd).