1. This can lead to spending too much time in the cyber world, and not enough time in the "real" world. This can lead to decreased productivity (for example, not completing homework, or even remembering to eat, in extreme cases).
2. When engaging in a social media relationship, "catfishing" (when someone has a fake profile and pretends to be someone else) is a common occurrence.
3. Something more extreme than catfishing can also occur, often with younger adolescents. While it can be categorized as catfishing, the person behind the profile could be a predator and have plans to abduct the other person.
4. "Real world" relationships may suffer. Social media relationships require a lot of time on the computer/phone, which may take away time from hanging out with friends and family (similar to the first point).