This post by the man with the black hat hits the nail on the head when he writes:

But if the example of Dorothy Day and Peter Maurin are any indication, we don't need the bishop's permission, or a masters in theology, to perform the corporal and spiritual works of mercy in our lives.

and later:

There was a time when, for a group to publicly call itself "Catholic," it had to obtain the permission of the local bishop. This manner of structuring the lay apostolate, known as "Catholic Action," ensured the integrity of identity of the endeavor or endeavors. That way, if you were in the business of, say, placing children for adoption, there was a priority on placement in homes dedicated to sharing with these little ones the gift of the Faith. This, as opposed to whatever your Federal grant money, or some feminazi nun with an attitude problem, told you to do (unmarried couples, gay couples, et cetera). Or if you were a doctor who worked at a free clinic operating as "Catholic," it was safe to say you weren't handing out condoms. But it's different now. Even an "official" Catholic charitable work is problematic. You can read all about them in the Catholic blogosphere.