When people who have become friends through the website Yelp
plan private outings only to have them stormed by other, uninvited members of the community just because they heard about it by association or word of mouth that 'leaked'.
And therefore turning a small, private gathering of friends who met through Yelp into something that is invaded by other uninvited Yelp members who feel entitled to join due to acquaintance and thinking everything is a Yelp event when in fact, it's not always.
"I want to invite a bunch of people to have drinks out for my birthday, but I don't know what to do if Yelpers Mark and Ronald find out - I don't want them to spread the word and turn this small gathering into a giant Yelp Gangbang. What a headache."