With the help of its multilingual readers and Google Insights, a tool that tracks Web searches by time and location, KnowYourMeme pieced together a timeline: It started in 2004, on 2chan.net, a so-called imageboard in Japan that allows users to post images anonymously — essentially a petri dish for meme manipulators.

Who first found Stephen’s picture is not known, nor how it was found. What’s known is that a 2chan user superimposed Stephen’s face over an illustration from a manga comic book, and turned it into an image macro — a simple Web form that allowed users to put words into a cartoon-like thought bubble. The meme-ification of Stephen began.

As Mr. Rout uncovered new permutations of the meme, he was anything but freaked out. An Internet dweller since the days of Usenet, he wasn’t afraid for Stephen’s safety. Plus, he knew that there was nothing he, or any parent, could do to prevent the use (or misuse) of an image of his child, once it was uploaded to the Web.