In Monday's National Catholic Reporter, Michael Sean Winters recalled a previous debate with Acton Institute founder Fr. Robert Sirico and announced a conference at Catholic University of American mounting the Catholic Case against libertarianism. You can read his screed at http://ncronline.org/blogs/distinctly-catholic/catholic-case-against-lib...
Don't confuse Acton with Libertarianism generally. There are many flavors of it. As for being guilty of heresy, MSW is the last person who could be accused of that. Indeed, a little creativity in challenging the bishops and their relationship with the GOP might come in handy. As for the concept that there can be economic heresy - yes there can be. Simony is a start and generally making the Church dependent on the rich so that they do not speak the truth in the Church's prohetic voice should be regarded as heretical - not from the hard letter doctrines of the Church but from the Bible and our history.
Back to Acton, it is hardly a major force in libertariansim, except in its own mind. There are some libertarians who defend capitalism, but there are others who denounce crony capitalism which is part of its globalist nature. Most of them are intellectually lazy, conflating the free market with capitalism. Capitalism is not a free market exercise - it is about cornering markets of goods and creating a less than gree market for jobs so that workers can be controlled (no liberty there). Of course, in the Church, there are the Distributists (Chestertonians, etc) who chear for Subsidiarity and for as small and local economy as you can get - hardly globalists.
I wonder if anyone at the CUA conference attacking libertarianism will include anyone who represents other strands of it than MSW believes exist. Indeed, in a libertarian socialist model, like, say, Mondragon, the Church and the cooperative play major roles in doing things that the state would other wise do (and do badly). Part of Libertarianism IS shifting from government to Church those things the Church does best. Let's not throw out the baby with the bath water.
The vocal nature of Acton and other Catholic libertarians no doubt reflect the views of their funders (could therer be a Koch someplace near?) but are mainly a holding action following Pope Benedict's Caritas in Veritate and most of what Pope Francis says. They are screaming loudly because they are in trouble. It won't help them.
Efforts to demonize liberty won't help either. Just as you can't have subsidiarity without solidarity, you can't have solidarity without subsidiarity (it gets nasty if you try). Neither liberty or socialism will long succeed without the other.
The Church won't be much of a Church if it condemns Americanism - not the foreign policy variety but the view that somehow American bishops can relate to the Vatican differently because of the nature of the polity. First, such crackdowns led to a nasty string of teaching that demonized sex, including and especially masturbation as a mortal sin (when in Scripture the penalty for it was taking a warm bath). Second, if there is an Americanism that requires a difference in how doctrine relates to our legalism, then the best thing to do is not condemn it but understand it, along with Modernism. Until they do, they won't understand the law and politics on abortion in this country (which is emerging in other Republics) nor will they understand that they cannot fight the progess of archeology, anthropology, history and religious studies. In Gaudium et Spes and other places, they talk about our first parents and Adam and Eve. Science teaches us that no such people existed in some kind of golden age. While Adam and Eve are good myths on human nature, their equation with the first homo sapiens does not exist and the Congregation for the Doctrine of Faith needs to grow up and recognize that they did not.