You shouldn't fall for someone you don't know.
Mark is lonely and only has strangers as Facebook friends, and they are the only people he talks to.
Mark wants to build a relationship with someone off Facebook.
Mark decides to have a platonic, casual friendship with someone from his Facebook network.
Mark starts a romantic relationship with a stranger from his Facebook network.
Mark and his friend have a lot of good chats together online.
The romance falls apart due to lack of knowledge about each other and Mark feels bad.