At this point, the whole Improv Everywhere phenomenon has sort of even itself out on the spectrum of annoying vs. adorable. It’s the Ben Linus of flash mobs: Sometimes working on the side of good (like the spontaneous Ghostbusters raid of the New York City library), sometimes evil (like when Fox used the concept as a viral marketing stunt for Glee in Italy). For the most recent example of the gray territory Improv Everywhere inhabits, check out their most recent Star Wars-themed stunt on this NYC subway.
You’d think at this point the “normals” wouldn’t be so surprised and delighted by the invasion as like “Meh, those guys again? I’m just trying to get to work on time.”