Someone who posts something random on your Facebook wall, or comments on a post for the sole purpose of being seen by
someone else/making their presence known. Usually done by an ex-gf/bf, a wanna-be gf/bf or in sneaky cases, by someone who wants you to friend them but does not want to send a
friend request for fear of being rejected, so posts it on mutual friend's page.
Usually this pop-up is ignored, like most screen pop-ups because it's an obvious "
look at me" attempt.