1. I do think that Christian leaders in Russia and internationally would do well to be heard condemning physical and verbal violence against those activists on the side of LGBT lifestyles, violence that appears from media reports to be at a significant level. This condemnation does not imply any withdrawal on their part from traditional Christian teaching on human sexuality; it is on the other hand a legitimate witness to the dignity of human persons whose beliefs on this matter are different from their own. It represents a principle of non-discrimination at the heart of action on behalf of the human person - in the word used by the UN Universal Declaration of Human Rights, human rights are "inalienable", that is, they belong to each and every human person without exception.
2. It is also worth taking cognisance of Article 16, especially sub-section (3), of the UN Universal Declaration of Human Rights, recognising that the sense of this article applies to marriage as a union between a man and a woman:
(1) Men and women of full age, without any limitation due to race, nationality or religion, have the right to marry and to found a family. They are entitled to equal rights as to marriage, during marriage and at its dissolution.
(2) Marriage shall be entered into only with the free and full consent of the intending spouses.
(3) The family is the natural and fundamental group unit of society and is entitled to protection by society and the State.Whatever one might make of the motivations of the Russian politicians and the circumstances under which they enacted their law which is the subject of todays protest, that law can be seen as a provision to protect marriage and family life as envisaged by sub-section 3.
One might put it against Article 19's assertion of a right of exchange of information; but there is provision within the UN Declaration at Article 29 for limitations of rights in order to meet the requirements of "the general welfare in a democratic society", which might well be seen as applicable in this case:
Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.3. Following the example of Auntie Joanna, this appears an appropriate time to post the text of the teaching of the Catechism of the Catholic Church (scroll down from this link to find the relevant paragraphs) on this question:
2357 Homosexuality refers to relations between men or between women who experience an exclusive or predominant sexual attraction toward persons of the same sex. It has taken a great variety of forms through the centuries and in different cultures. Its psychological genesis remains largely unexplained. Basing itself on Sacred Scripture, which presents homosexual acts as acts of grave depravity,140 tradition has always declared that "homosexual acts are intrinsically disordered."141 They are contrary to the natural law. They close the sexual act to the gift of life. They do not proceed from a genuine affective and sexual complementarity. Under no circumstances can they be approved.
2358 The number of men and women who have deep-seated homosexual tendencies is not negligible. This inclination, which is objectively disordered, constitutes for most of them a trial. They must be accepted with respect, compassion, and sensitivity. Every sign of unjust discrimination in their regard should be avoided. These persons are called to fulfill God's will in their lives and, if they are Christians, to unite to the sacrifice of the Lord's Cross the difficulties they may encounter from their condition.
2359 Homosexual persons are called to chastity. By the virtues of self-mastery that teach them inner freedom, at times by the support of disinterested friendship, by prayer and sacramental grace, they can and should gradually and resolutely approach Christian perfection.