"From a legal point of view, chilling effect may be defined as the negative effect any state action has on natural and/or legal persons, and which results in pre-emptively dissuading them from exercising their rights or fulfilling their professional obligations, for fear of being subject to formal state proceedings which could lead to sanctions or informal consequences such as threats, attacks or smear campaigns. State action is understood in this context as any measure, practice or omission by public authorities which may deter natural and/or legal persons from exercising any of the rights provided to them under national, European and/or international law, or may discourage the potential fulfilment of one’s professional obligations (as in the case of judges, prosecutors and lawyers, for instance).
While there could be situations where state action might unintentionally produce a “chilling effect” on natural and/or legal persons, national authorities may also deliberately adopt measures, undertake specific actions and/or fail to react with the view of unlawfully dissuading lawful behaviours they do not approve of. Three main “techniques” to dissuade natural or legal persons from exercising their rights can be briefly outlined in this respect: (i) The adoption of deliberately ambiguous legal provisions; (ii) The arbitrary enforcement of these provisions against the most vocal critics of the autocratic-minded authorities of the day—be they opposition politicians, journalists, judges, prosecutors, lawyers, academics or civil society groups—if only to “send a message” to the public at large; (iii) The adoption of disproportionate sanctions, as this will in turn further discourage people from exercising their rights and/or obligations and therefore limit the need for future arbitrary enforcement of the relevant legal provisions whose lack of foreseeability is intentional.
In short, chilling effect is primarily about public authorities, directly or through proxies, aiming to create a climate of self-censorship regardless of whether the conduct being contemplated is protected under national and/or European law." (What is chilling effect, pages 4-5)