The Human Rights Committee underscores that the right of peaceful assembly is a fundamental human right that is essential for public expression of one’s views and opinions and indispensable in a democratic society.  Like freedom of expression, the right to freedom of peaceful assembly in particular also protects the right to express a view that others will disagree with. It is the duty of the authorities to permit this and indeed to protect the safety of those manifesting the controversial view.
The case of Alekseev v. Russian Federation was lodged with the Human Rights Committee by an activist who had been denied permission to picket in front of the Iranian Embassy in Moscow to express concern over the execution of homosexuals and minors in Iran. The local authorities justified their refusal by reference to the risk of a “negative reaction in society” that could lead to “group violations of public order”. The Human Rights Committee considered there had been a violation of the right to assemble and stressed the duty to protect the participants in such an assembly:
The Committee notes that freedom of assembly protects demonstrations promoting ideas that may be regarded as annoying or offensive by others and that, in such cases, States parties have a duty to protect the participants in such a demonstration in the exercise of their rights against violence by others. It also notes that an unspecified and general risk of a violent counterdemonstration or the mere possibility that the authorities would be unable to prevent or neutralize such violence is not sufficient to ban a demonstration … the obligation of the State party was to protect the author in the exercise of his rights under the Covenant and not to contribute to suppressing those rights. The Committee therefore concludes that the restriction on the author’s rights was not necessary in a democratic society in the interest of public safety, and violated article 21 of the Covenant.
The ECtHR has taken a very similar line. In Barankevich v. Russia, for example, the applicants had been refused permission to hold an Evangelical Christian service in public, on the grounds that the majority of the local residents professed a different religion and the service could thus cause discontent and public disorder. The ECtHR held that that amounted to a violation; they authorities should have taken reasonable and appropriate measures to enable the assembly to proceed peacefully:
It would be incompatible with the underlying values of the Convention if the exercise of Convention rights by a minority group were made conditional on its being accepted by the majority. Were it so a minority group’s rights to freedom of religion, expression and assembly would become merely theoretical rather than practical and effective as required by the Convention …
The Court stresses in this connection that freedom of assembly as enshrined in Article 11 of the Convention protects a demonstration that may annoy or give offence to persons opposed to the ideas or claims that it is seeking to promote. The participants must be able to hold the demonstration without having to fear that they will be subjected to physical violence by their opponents. It is thus the duty of Contracting States to take reasonable and appropriate measures to enable lawful demonstrations to proceed peacefully.
The ECtHR has further stated that the negative attitudes of others are no reason to move an assembly out of the city center:
[N}egative attitudes of others towards the views expressed at a public assembly cannot serve as a justification either for a refusal to approve such an assembly or for a decision to banish it from the city centre to the outskirts.