The social networking service takes several factors into consideration before designating an individual as "dangerous".

State's attorney general Letitia James on Thursday (local time) wrote on her official Twitter handle, "BREAKING: We're launching an investigation into Facebook's unauthorised collection of 1.5M of their users' email contact databases. Facebook has repeatedly demonstrated a lack of respect for consumer information while at the same time profiting from mining that data."

Facebook and Instagram on Wednesday suffered a major global outage. Users were unable to access the two platforms on their smartphones as well as on desktop. Messenger was also down for several users.