Si les contours de la liberté d’expression sont régulièrement discutés ces dernières années, c’est le plus fréquemment s’agissant de la régulation par le droit pénal de l’expression publique que les polémiques se font les plus vives. En effet, c’est assurément sous cette dimension, c’est-à-dire lorsqu’elle consiste dans l’extériorisation directe de la pensée dirigée vers un public indéterminé, que l’expression emporte ses répercussions les plus spectaculaires au sein d’une société. Source de mobilisations citoyennes et d’une réflexion collective aux fins de l’élévation des mentalités vers le bien commun, l’expression publique peut également constituer le ferment de comportements antisociaux par l’alimentation des inimitiés, de l’intolérance et d’un état d’esprit criminel. Partant, la pénalisation, qui désigne l’ensemble des processus d’intervention du droit pénal dans un domaine déterminé, se trouve pleinement légitimée face aux dangers d’une expression publique immodérée. Toutefois, la pénalisation peine à trouver ses repères dans l’établissement des critères de sa nécessité et de son opportunité, à une époque où la place prise par l’expression publique au sein de notre société apparaît, plus que jamais, prépondérante. La pénalisation de l’expression publique est d’abord mise à l’épreuve de son instrumentalisation. La norme pénale semble en effet souffrir, de nos jours, d’une surestimation de ses vertus régulatrices dans sa création et dans sa mise en oeuvre en matière d’expression publique. La pénalisation de l’expression publique est ensuite mise à l’épreuve de la modernité. L’évolution des techniques place en effet l’expression publique au cœur d’une mutation profonde de ses usages au sein de notre société, modifiant les paradigmes classiques du rapport entretenu par celle-ci avec le droit pénal. / While the contours of freedom of expression have been regularly discussed in recent years, it is most frequently in the case of the regulation of public expression by criminal law that polemics are most heated. Indeed, it is certainly under this dimension, that is, when it consists in the direct exteriorization of thought directed towards an indeterminate public, that the expression has its most spectacular repercussions within a society. A source of citizen mobilization and collective thinking for the purpose of raising mentalities towards the common good, public expression can also constitute the ferment of antisocial behaviour by feeding enmities, intolerance and a criminal state of mind.Consequently, penalization, which refers to all the processes of criminal law intervention in a given field, is fully legitimate in the face of the dangers of immoderate public expression. However, penalization is struggling to find its bearings in establishing the criteria of its necessity and timeliness, at a time when the place taken by public expression within our society appears, more than ever, predominant. Penalization of public expression is first put to the test of its instrumentalization. The penal norm seems to suffer, nowadays, from an overestimation of its regulatory virtues in its creation and in its implementation in the area of public expression. Penalization of public expression is then put to the test of modernity. The evolution of technology places public expression at the heart of a profound change in its uses in our society, modifying the classic paradigms of the interplay between public expression and criminal law.

The subject of this diploma thesis is the potential of organizations of civil society to influence public debate about immigration to Europe via Facebook. Conclusions introduced in this diploma thesis are based on my own empirical research as well as on literature focused on public relations. Research is designed as single case study of Facebook communication of Doctors without Borders. I explore the diversity of topics and argumentation present in the organization's communication, reactions of its audience and mutual interactions between organization and its audience. I explain that content, visual and formal aspects may play a key role when an organization is trying to address wide audience, whose ideas is willing to shape and influence. Research points out that the communication of Doctors without Borders about migration to Europe is one-sided, because it's mainly driven by activities and mission of the organization. This one-sidedness is partly compensated by engaged audience that enriches discussions under the Facebook posts of the organization with diverse topics and opinions. The thesis tries to capture the significance of tension between organization and its audience that raises inspirational discussions, which might not occur in case of absolute consensus. Key words communication, public...