Our colleagues at NextRound have, er, rounded up some terrifically candid photobombing shots. For the uninitiated, photobombing is the practice of clandestinely (sometimes unintentionally) inserting oneself into the backdrop of a photograph being taken by strangers. Our favorite entry from the listicle featuring 20 of the All-Time Greatest Photobombers illustrates the concept very well. Notice the topless beach bomber: