public safety and the rights and freedoms of others. Wherever legitimate restrictions are imposed concerning the time, place and manner of a peaceful assembly, human rights defenders holding an assembly must be provided with reasonable alternatives that ensure that the assembly can be held within “sight and sound” of the target audience. States should ensure that appropriate and effective procedures are in place to review complaints about the imposition of undue restrictions. Authorities should also refrain from obstructing participation in assemblies and imposing unreasonable requirements on the organizers of assemblies that would discourage them from holding assemblies. 58. Spontaneous assemblies should be facilitated, in line with the presumption in favour of holding assemblies, even where no advance notification was given. Human rights defenders participating in non-notified assemblies should not be arrested, detained or fined solely for their participation in such an assembly. Fines or other sanctions for failing to comply with formal legal requirements for assemblies should be proportionate to the gravity of the offence; legislation that allows for disproportionate penalties should be repealed. Under no circumstances should organizers of peaceful assemblies be held liable for unlawful acts by individual participants if they make reasonable efforts to avert them. States should ensure that all those charged with administrative or other offences in connection with the exercise of their right to freedom of assembly enjoy full due process protections. 59. In policing assemblies, law enforcement officers must strictly refrain from using force against human rights defenders who exercise their right to peaceful assembly. Particular attention should be given to specific needs – for example, in terms of risk assessment, the composition of police units or their prior training and instruction – when policing assemblies of certain groups of human rights defenders who are at particular risk. If assemblies turn violent, the police have a duty to use force only where strictly necessary and only to the extent required by the exigencies of the situation. They must refrain from using disproportionate force and indiscriminate force that fail to distinguish between violent and peaceful demonstrators, journalists reporting from the event, monitors or bystanders. Any misconduct and excessive use of force by law enforcement officers must be promptly, effectively and independently investigated and appropriate action must be taken to bring those responsible to justice. Law enforcement officers must be regularly and sufficiently trained to ensure their compliance with human rights principles in policing assemblies. States should involve human rights defenders in devising and implementing such trainings. 60. Furthermore, states have a positive obligation to protect human rights defenders from any acts by third parties that aim to obstruct them in exercising their right to peaceful assembly, without discrimination. This includes physical protection before, during and after the assembly if those organizing or participating in it face threats of violent attacks. This is particularly relevant for assemblies on issues that are perceived to challenge traditional values or aim to counter extremist political 12 Guidelines on the Protection of Human Rights Defenders