Libel and personal damage. Fake profiles are used to damage reputation or ridicule someone in public, simply out of revenge, or in order to blackmail them. This is not just an issue for celebrities. For example there have been a number of incidents reported of profiles being used to ridicule teachers or fellow pupils in schools.
Phishing. Such profiles can be used to lure unsuspecting users into divulging information which can be used for phishingattacks. For example, by masquerading as a person’s offline friend (which is not difficult to do), it is possible to trick them into giving out location data.
Marketing under false pretenses. False profiles are used to advertise products while pretending to be a "friend" of the target.
Legal action against perpetrators with no malicious motives. Setting up fake profiles may be seen as a fun activity which may even have educational value.[1]