GENEVA: A United Nation's expert has written to Facebook CEO Mark Zuckerberg and urged him to narrow its "overyly broad" definition of terrorism and the apparent lack of a comprehensive human rights-based approach to the policies governing access to and use of its platform.Fionnuala Ní Aoláin said that Facebook wrongly equates all non-state groups that use violence in pursuit of any goals or ends to terrorist entities.The special rapporteur on the promotion and protection of human rights and fundamental freedoms while countering terrorism said, “The use of overly broad and imprecise definitions as the basis for regulating access to and the use of Facebook’s platform may lead to discriminatory implementation, over-censoring and arbitrary denial of access to and use of Facebook’s services.”"The use of such a sweeping definition is particularly worrying in light of a number of governments seeking to stigmatize diverse forms of dissent and opposition – whether peaceful or violent – as terrorism,” said Ní Aoláin.Facebook defines terrorist entities as: “Any non-governmental organisation that engages in premeditated acts of violence against persons or property to intimidate a civilian population, government, or international organisation in order to achieve a political, religious, or ideological aim.”“The use of such a sweeping definition is particularly worrying in light of a number of governments seeking to stigmatize diverse forms of dissent and opposition – whether peaceful or violent – as terrorism,” said Ní Aoláin.The special rapporteur expressed concern at the lack of clarity about the methods by which Facebook determines when a person belongs to a particular group and whether the respective group or person are given the opportunity to meaningfully challenge such determination. The absence of any independent processes of review, oversight and monitoring of Facebook’s actions is also highly problematic, she added.Ní Aoláin urged Facebook, as well as any other companies facing similar challenges, to adopt the model definitions of terrorism and incitement to terrorism developed by the mandate of the Special Rapporteur.Earlier, the UN human rights chief had urged Facebook to proactively address hate speech and warned against excessive regulation, after US President Donald Trump accused tech giants' platforms of bias against him.Zeid Ra'ad Al Hussein's appeal followed a decision by Facebook to ban Myanmar's army chief and other top military brass named in a UN probe linking them to a possible "genocide" against Rohingya Muslims.