In semi-rare cases, majorities organise against minorities. If that happens and the majority gets access to the data stored in something like Facebook's databases, it will be catastrophic. We can't say what minority it will be either. Rich people? Gypsies? Foreigners? Farmers? Poor people? They've all been persecuted groups at some point or another in some country.

This isn't comparable to something like not being able to repair my phone, requiring me to buy a new phone.