People who respond inaccurately to Facebook events. This includes:
- People who RSVP "attending" and then don't attend.
- People who just don't respond to anything, therefore electing to stay in the "awaiting reply" category.
- People who say "may attend" to absolutely everything.
This is frustrating because many users, including people and businesses, use Facebook as their main way to announce events these days. People say yes (possibly so as not to hurt the person's feelings) with no intention of attending, and this leads to confusion (and potentially disappointment) on the event planner's part.
I'm just saying, if you don't plan on going to the event, don't say yes or maybe. Say no, or if you don't want to be listed in the "no" section, remove yourself from the event. It makes for a much more pleasant experience all around.